Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
I lB4~2}
FIELD OF THE I~ NTION
The present invention relate~ to a power ~upply
arrangement for an optical apparatus, and more particularly;
to a power supply arrangement for use a plurality of load to
be supplied the electrical energy.
BACKGROUND OF THE INVENTION
In recent years, the flash apparatus has ~een
widely employed in various kinds of optical apparatus which
require a flash of light. Particularly, in the art of phot-
ography, artificial light is used to illuminate an object tobe photographed. One form of artificial light which is now
widely used is so-called electric flash device~ It is
common practice in electric flash devices to obtain high
intensity illumination for photographic purposes by dis-
charging a charged capacitor through a gas-filled flash tube.
A low voltage D.C. power source IS generally employed together
with suitable circuitry in order to obtain the relatively
high D.C. voltage which is needed to charge the flash capac-
itor for firing the flash tube. Since an electric flash
device o~ thi~ type iB generally portable, a battery operated
power supply is usually employed as a power source of the
electric flash device.
In the battery operated power supply, a D.C. - D.C.
convexter i~, generally, employed in order to regulate a
voltage from a battery. High D.C. voltage is obtained from
the battery through the use of a voltage converter. A con-
verter inclllde3 a transformer for converting low D.C. voltage
to high A~C~ voltage, and a rectifier circuit for rectifying
the A.C. voltage, the rectified voltage being then applied
to a fla~h capacitor in order to charge it. The power
~upply of this kind of the load employs a D.C. - D.C.
~A~
~ 164~
converter which comprises a direct current power ~ource
circuit havin~ a battery, a voltaye converter circuit for
converting a direct current output voltage to an alternatirly
current voltaye, a rectifier circuit for rectifying the
alternating current voltage in-to a direct current voltage.
Electric flash un:its employ a power supply usual:Ly
wherein a large output capacitor is charged, over a period of
time, to a voltage of sufficient amplitude to supply a photo-
flash lamp. These power supplies usually employ a mechanical
vibrator for the purpose of converting a relatively low
battery volta~e to the relatively high unidirectional voltage
required for a load such as, for example, the photoflash lamp.
It can readily be understood that under ordinary circumstances
when an electric flash device is being used, a substantial
portion of the time during which the device is turned on may
be standby time, that is, time which elapses after the power
supply has charged the capacitor to a suitable value and
before the carnera shutter is tripped thereby discharging the
capacitor through the flash tube. During this time the power
supply consumes energy from the battery without producing
any useful result. The energy loss may be significant, par-
ticularly when the device includes a transformer. As the
batteries age their output voltage drops and a longer period
of time is required for firing the flash tube. In addition,
the device becomes incapable of flashing the flash tube.
Particularly when the electric flash device is used;
in the camera equipping other load equipment such as, for
exarnple a data recorder or a motor driving device, it is
necess~ry to use a power supply in common with the electric
flash unit and the other :Load equipment. In this case, the
data recorder or the motor driving device must be driven
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by an identical power supply, immedia-tely after the flash tube
generates the flash liyht. It is difficult to drive both
the flash tube and the data recorder device or the rnotor
driving device, because of the large arnount of power required
to opera-te the fLash tube~ Accordingly, it is neees,sary to
cause the power supply for flash tube to its OFF state during
the activation of the data recording device or the motor
driving device and to make the charging time of a charging
circuit of the flash device short, in order to smookhly
perforrn the activa-tion of the flash device and other load
equipment.
OBJECT OF THE INVENTION
The prir~ry objeet of the invention is to provide
a power supply arrangement for an optical apparatus which can
effeetively operate a plurality of load equipment by eontrol-
ling the O~-OFF timing automatically.
Another objeet of the present invention is to pro-
vide an economieal and high performance power supply arrange-
ment whieh eonsumes a small amount of electrieal energy to
supply to a load circuit, by interrupting the current to
be supplied to one load equipment during the time in which
the other load equipment is actuated, and which is e,asy to
operate as well as being convenient to use.
SUMMARY OF '~E INVENTIO~
In accordance with a particular embodiment of the
invention there is provided a power supply arrangement Eor
a flash device. The arrangement includes a direct current
power souree, a converter for converting a direct current
voltage froTn the direct current po~Jer source to an alternat-
ing current voltage. A rectifier rectifies the alternatingcurrent voltage and a main capacitor is arranged to be charged
-- 3 --
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by way of a rectifier. A first load includes a flash tube
and a trigger signal generator is provided for inltiating
the discharye of the main capacitor into the firs-t load. A
second load is connected to the current power source, and
a control circuik, including a con-trol switching element,
is connected to the converter and a capacitative-resistive
timing network. The capacitor of the tirning network i3
arranged to be charged as the main capacitor i5 charged.
Means are provided for activating the control switching
element of the control circuit by discharging electric charge
of the capacitor of the timing network in response to the
discharge of the main capacitor and for controlling the
operation of the converter temporarily. Thus, voltage drop
of the direct current power source is made less by making a
current flowing to the converter decrease when the second
load operates and during the time the switching element
activates.
In accordance with a further embodiment of the in-
vention there is provided a power supply arrangement for a
flash device. r~he arranyement includes a direct current
power source and a converter for converting a direct current
voltage from the direct current power source to an alternat-
ing current voltage. A rectifier rectifies the alternr~ting
current voltage and a main capacitor is arranged to be charged
by way of the rectifier. A first load is provided, and a
trigger signal generator is also provided for initiating the
discharge of the rna:in capacltor into the first load. A second
load i~ connected to the current power source and a control
circuit, including a control switching element, is connected
to ~le converter an~ a capacitative-resistive timing network.
r~le capacitor of the tirning networX is arranged to be charged
2 ~
as the main capacitor is charged, and means are provided for
activating the control switching element of the control c.ir-
cuit by discharging electric charye of the capacitor of the
timing network in response to actua-tion of rneans for activat-
ing the trigger signal yenerator and for controlliny the
operation of the converter temporarily. Thus, voltage drop
of the direct current power source is rnade less b~ rnaking a
current flowing to the converter decrease when the second
load operates and during the time the switching elernent
activates.
In accordance with a still further embodiment of the
invention there is provided a power supply arrangement for a
flash device. The arrangement includes a direct current power
source circuit including a battery for providing a direct
current voltage. A converter circuit converts the direct
current voltage from the direct current power source circuit
to an alternating current voltage. The converter circuit
includes an oscillator circuit, a rectifier circuit for
rectifying the alternating current voltage, and a charging
circuit for storing electric charge and for supplying elec-
trical energy to a flash tube circuit. I'he charying circuit
includes a main storage capacitor and a first load circuit
including a trigger signal generating circuit and a flash tube
of the flash tube circuit. An oscillating control circuit
includes a voltage detection circuit for detecting -that a
voltaye o~ khe rnain storage capacitor of the charging circuit
~ecome3 a predete~Mined value. An oscillation stop timing
performing circuit i~ provlded for performin~ repetition of
on and off of the converter circuit. The oscillator circuit
of the converter circuit includes an oscillation switch ele-
ment functioning as a high value resistor when the oscillat-
2 ~
ing operation of -the oscilla-tor circuit ceases. A bia~
control swi-tch element is provided for controlliny on and
off operations of the oscillation switching elernent. ~he
oscillation control circuit includes a voltaye detecting
element for de-tecting that the voltaye of the main storage
circuit of the charging circuit become~ the prede-termined
value and for controlling the bias control switch element
of the oscillator circuit.
Certain ernbodiments of the invention will now be
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described by way of examples and with reference to the accom-
panying drawings, where:in li~e parts in each of the several
figures are identified by the same reference characte~r and
wherein:
F.iyure 1 is a detailed circuit diayram of power
supply arrangement for an optical apparatus accordlng to the
present invention;
Figure 2 is a detailed circuit diagram of another
power supply arrangement for an opt.ical apparatus according
to the present invention, and
Figure 3 is a detailed circu.it diagrarn of yet
another power supply arrangement for an optical apparatus
according to the present invention.
Referring to Figure 1 of the drawings, there is
shown a power supply arrangement for a:n optical apparatus.
The power supply arrangement shown in Figure 1 comprises a
direct current power source circuit A which includes a battery
10 and a power source switch 11 which is manually operated,
a voltage converter
~ ~b -
116~
circuit B for converting and boosting the ~oltage frorn the
direct~current power source circuit A into an alternating cur-
rent voltage, a rectifier circuit C for rectifyiny the boo~ted
alternating current voltage from the volt~ge converter circui.t
B, a charging ci.rcuit D for storing electrical energy supplied
in the form of direct current from the rectifier circuit C and
for supplying the electric energy to a first load circuit F
which includes a flash tube, a trigger signal generating circuit
E for triggering the flash tube by applying a triggering signal
to a trigger electrode of the flash tube, an oscillation control
circuit G for controlling the voltage converter circuit and a
second load circuit H to be driven by the direct-current power
source circuit A in common with the flrst load circuit F.
The direct-current power source circuit A comprises
a battery 10 and a power source switch 11 which is connected in
series with the battery 10. The voltage converter circuit B
comprises, substantially, an oscillator circuit OC, an oscilla-
tion starting circui~ OS. In more detail, the voltage converter
circuit B includes an o~cillating transformer 12 having at
least two winding such as a primary wi.nd.ing 12a, a secondary
winding 12b and a third winding 12c, an o~cillation switching
element in the form of a high performance sillicon tran~istor 13,
an oscillating capacitor 14 and a current-restricting resi~tor
15. One terminal o-f the primary winding 12a is directly con-
nected to a positive terminal of the battery 10, and other ter-
minal of the primary winding 12a i8 connected to a collector
electrode i.n ord~r to form the oscillator circuit OC. One
terminal o~ the ~econdary winding 12b is connected to one termi-
nal of the third windiny :L2c, and other terminal of the third
winding 12c i~ connected to a juncture Jl of the primary windiny
12~ and the re~i~tor 15 in
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order to constitute the oscillation startiny OS.
rrhe converter circuit B i~, substarltially, a vol-
tage feedback type oscillator circui-t. The oscillating
transistor 13 is of a hiyh performance NPN type, as is ex-
plained herelnabove, and has high i.nternal resistance when
it is cut-off state. Accordingly, the lea'kage current of the
transistor 13 is extremely small and is nearly zero in com-
parison with that of the Germanium transistor.
The rectifier circuit C,includes an electric valve
in the form of a diode 16 of which a cathode electrode is
connected to other terminal of the secondary winding 12b
of the oscillating transformer 12, and the diode 16 is pro-
vided so as to be reverse direction with respect to the pol-
arity of the battery 10 of the direct current power source
circuit A. The charging circuit D cornprises a main storage
capacitor 17, a current-restrictlng resistor 18 and an in-
dicating lamp in the form of a neon glow lamp 19 which is
connected to the main storage capacitor 17 by way of the cur-
rent restricting re4iqtor 18. One terminal of the capacitor
17 is connected to an anode electrode of the diode 16, and
the other terminal of the capacitor 17 is connected to the
emitter electrode of the oscillating transistor 13 and to a
negative terminal of the battery 10 by way of the power source
switch 11.
The trigger pu].se generating circuit E has a charg-
iny re~ tor 20 o~ which one terrninal is connected to the one
terminal o the main storage capacitor 17, a triggering cap-
acitor 21 of which one terrninal is connected to the other
tenninal of the charging resistor 20, a triggering trans-
30 former 22 having a primary winding 22a and a secondary 22b,
and a ~ynchronizing .switch 23 which is arranged to be
~wikched O~J and OFF in synchronizing with a camera shutter.
~3 ''~'' ~ 6 -
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~ ~B~21
The first load circuit F includes a ~as-filled flash tube 24.
The flash tube 24 is provided with a pair of main current
conducting electrodes 2~a, 24b and a trigger electrode 27c
which is positioned adjacent but exterrlal to the flash tube
24~ The trigger e].ectrode 27c is connected to one tertninal
of the secondary windi.ny 22b of the -triggering transformer
22, and one main current conducting electrode 24a is conn-
ected to other terminal of the secondary winding 22b.
The oscillation control circuit G comprises a
charging resistor 25, an osclllation control capacitor 26 and
a control switch element in the form of an oscillation con~
trol transistor 27. One terminal of the oscillation control
capacitor 26 is connected to a base electrode of the oscill-
ation control transistor ~7 of which collector-emitter path
is connected to the oscillating capacitor 1~ of the voltage
converter circuit B in parallel relatfLonship, and the other
terminal of the oscillation control capacitor 26 is connected
to a juncture J3 located between the diode 16 and the main
storage capacitor 17 by way of the charging resistor 25 to
form the oscillation control circuit G.
The second load circuit H is also actuated by the
direct current power source circuit A. A data recording
device K is provided as the second load circuit H, and com-
prise~ an illuminating larnp 34 which is connected to the
direct current power source circuit A by way o~ a driving
~witch 33 actua~ed in synchronizing with the camera shutter,
a tran3~ucent data plate 35, carrying the data to be
recorded, and provided at the front of the lamp 3~, a fo-
cusing len~ 36 po~itioned between the data plate 35 and a
film 37.
In operation, the power source switch 11 is man-
ually operated by it~ ON and OFF starter. When the ~witch
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11 is in its OFF state, the oscillator circuit OC does not
also activate is osc:illating operation, because the power
source current is not connected to the voltaye converter
circuit B. ~y turning the power source switch 11 ON, the
base electrode of the transis-tor 13 i~ biaserl to cause the
transistor 13 to become conductive, since the base current
is supplied to the transistor 13 from the battery 10 of the
power source circuit A by way of the resistor 15 and the third
winding 12c of the oscillating transformer 12. When the
transistor 13 turns ON, current Elows through the primary
winding 12a of the oscillating transformer 12, the collector-
emitter pa~h of the transistor 13 from the battery 10 and, at
the same time, the current flows through the third winding 12c,
the base-emitter path of the transistor 13, the battery 10
and the resistor 15, and the electric charge is accumulated
on the oscillating capacitor 14 at the polarity as shown in
Figure 1, and thereby the voltage converter circuit B comm-
ences the oscillation and high alterna~ing current voltage
i.s produced from the secondary windiny 12b o~ the oscillating
trarlsformer 12. In this case, the os~illating voltage due
to the stray capacity of the windings of the transformer 12
or the oscillating capacitor 14 is also employed to facilitate
the ON and OFF operation of the oscillating transistor 13.
The high alternating current voltage is rectified by the diode
16 of the rectifier circuit C, to produce a high direct
current vo.Ltage.
~ s each winding of the oscillating -transEormer 12
is wsund so that the base current increases, the trans.istor
L3 becomes conAuctive h~ means of positive feed-back opera-
tio~ of the transformer 12. The collector current almostlinearly increases with respect to time and the induced
5~1
voltage in the third winding 12c. The transient component
of the base current of the transistor 13 decreases when the
base current reaches to a peak value which peak value is
determined by the induced voltage and the value of resistor
15. That i5 -to say, the increment of the collector current
becomes non-linear, and does not increase any longer.
Accordingly, the induced voltage at the third winding 12c de-
creases, and thereby the base current of the transistor 13
decreases, and then the collector current decreases swiftly.
Due to the decrement of the collector current, the transistor
13 is cut-off.
When the transistor 13 is in the non-conductive
state, the current flowing through the third winding 12c of
the oscillating transformer 12 is swiftly interrupted and
then the energy l/2Ll x Ip2 stored on the oscillating capac-
itor 14 appears at the third winding 12c as a reverse voltage
with respect to the oscillating transistor 13 and the electric
charge is stored on the oscillating capacitor 14. (Ll is an
inductance ~H] and Ip is a peaX value of the collector
current). In this case, the charging current o~ the capacitor
14 becomes oscillating current if leaving as it is, because
the tranqistor 13 is cut-off. Under these conditions, the
current which flows in the primary winding 12a of the oscill-
ating transforrner 12 is also reversed at a half cycle of the
oscillation of the charging current, and the voltage appears
at the third win~ing 12c due to that current so as to bias
the ~r~n~i~tor 13 forwardly. The transistor 13 is, therefore,
biased again to be conductivc state.
The alternating current voltage induced at -the
3~ ~condary ~inding 12b i~ rectified by the diode 16, and there-
by the current flows in a current loop formed by the secon-
' ': -- g 21~
) 1645~1
dary winding 12b of the oscillating transforMer 12, thebase-emitter path of the oscillating transistor 13, -the
rnain storage capacitor 17 and the diode 16. By this
current, the electric charge is stored on the rnain storage
71 ~
9a -
t 1~52 ~
capacitor 17 o~ the charging circuit ~, at; a polarity s~s flhown ln
~i`igure 1, and, at the ~;ame tir~e, the elect;ric charge i~ aLso
accumulated on the oscillation control capacitor ~'~ o~ the osci-
llator control circuit; ~, at -the polari-ty as shown in the draw-
ing. ~i'urther, the electric chslrge iS storecl on the trig~gerirl~7capacitor 21 due to the current I~lowin~,~ through fl current loop
consis-tin~ of the secondary winding 12h, the base-emitter pa-th o~
the transistor 13, the triggering capacitor 21, the chargin~
resistor 20 and the diode 1~, owing to the recti~ying operation
o~ the recti~ier circuit a.
When the main storage capacitor 17 is :eully charged up to the
predetermined and suitable voltage, the neon glow lamp 19 lights
- indicating that the device is in readiness for the ~lash tube 24
to be ~ired. The ~lash tube 24 may then be ~ired by closing of
the switch 23 in synchronizing with the camera shutter. It will
be appreciated that this closing need only be momentary during
the actuation o~ the camera shutter. By closing the switch 23,
the electric charge on the tri~gering capacitor 21 discharges
through the ~witch 2~ and the prirnary winding 22a. Then high vol-
-tage pul~e ~uch a~ ~000 volt,~ induced at the secondary winding 22b
o~ the triggering transYorr~er 22 appears at the trig~ering electrode
24c o~ the ~lash tube 24 and ioni~es a portion o~ the gas in the
~]ash tube 24~ The main ~torage capacitor 17 then discharges
acro~s th~ betw~en the ruain curren-t conducting electrodes 24a
and 24b, producin~ a brilli.ant ~:La~h of illumination. A~ter the
rnairl )tora~e caplc:itor 17 has been discharged, a terminal voltage
o~ the maln ~tora~e capaci~or 17 becolne~ low, and thereby the
~lectric char~e ~torf3d on the o~cilLl-tion control capacitor 26 is
a,u~ornatic111y difJchs~r~d by way oI' thc base-ernitter path o~ -the
~,!,) of3cil'Latin~ tranlis-tur 13, (and th~ oscillating capacitor 14),
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the main storage capacitor 17 (the flash tube 24) and the
capacitor 26. By discharging of the capacitor 26, a positive
potential appears at the base circuitry of the transistor 27
and, as a result, the transistor 27 becomes conductive.
When the transi.stor 27 becornes ON, both of the base-emitter
path of the oscillating transistor 13 and the o~cillating
capacitor 14 are short-circuited and then the oscillating
operation of the oscillator circuit OC is stopped. Con-
sequently, the charging current to the capacitors 17, 21
and 26 is interrupted by the inactivation of the oscillator
circuit of the voltage converter circuit B. In this case,
the power of the battery 10 is not, also, supplied to the
first load circuit F.
On the other hand, the driving switch 33 is closed
in synchronizing with the synchronizing switch 23, in the
second load circuit H. By closure of the driving switch 33,
current is supplied from the battery 10 to the illuminating
lamp 34 to produce a brilliant light. The light produced
from the lamp 34 passes to the focusing lens 36 through the
data plate 35. A ~ocused li~ht by the lens 36 illuminates
the film 37 in order to photograph the data recorded in the
data plate 35. It will be appreciated that the other load
equipments may also be used instead of the data recording
device K.
The oscillation control transistor 27 is turned OFF
a~ter the time interval when the positive potential is
applied to the base electrode of the transistor 27, which
time interval is determined by the discharging characteris- -
tic3 of the oscillat.ion control capacitor 26, and the transis-
tor 27 is ~urned OFF when the base potential becomes zero.
After the transistor 27 is turned OFF, the oscillating
transi~tor 13 becornes conductive and the oscillator circuit
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-- 1 1 --
3 ~8~52~
OC begins again the oscillating operation to activate the
voltage converter circuit B. The s-top time duration of the
oscillator circuit OC may be set by deciding a resistance
value of the charging circuit 25 and a capacitance value of
the oscillating control capacitor 26.
In accordance with the power supply arrangement of
Figure 1, since the high performance transistor 13 is employed
in the oscillator circuit ~~ of the voltage converter circuit
B, the loss of energy is prevented even when the power source
switch 11 is left in its 0~ state for a long tiTne period.
Further, the circuit construction is simplified and is eas~
to manufacture and is economical because the voltage conver-
ter circuit B is automatically operated in its ON and OFF
operations without using any mechanical switch in the voltage
converter circuit B.
Furthermore, the power supply arrangement shown in
Figure 1 is convenient to operate the plurality of load
equipments ~ well as the high reliability, because the
oscillator circuit OC can be automatically made ON and OFF.
Figure 2 shows a modification of a power supply
arrangement for an optical apparatus of Figure 1. In accord-
ance with the power supply arrangement of Figure 2, an
oscillation control circuit G is provided between an oscill-
ator circuit OC of a voltage converter circuit B and a trigger
signal generating circuit E. In rnore detail, an oscillation
control s~ ch element in the form of an oscillation control
transistor 27 is connected so as to be connected in parallel
relationship with respect to the oscillat.ing capacitor 14 and
base-emitter path of the o~cillating transistor 13. The
oscillation control capacitor 26 is connected between a base
electrode and a juncture J4 of the charging resistor 20
an~ the triggering capacitor 21 through the charging resistor
~,
- 12 -
.
25 in the trigger signal generating circuit E.
According to the power supply ~rranyement of
Figure 2, when the main s-torage capacitor 17 is fully ch~ryed
up to the predetermined voltage value, the electric charge
is stored on the capacitor 26 of -the oscillation control
circuit G at the polarity as shown in Figure 2. The eleckric
charge of the main storage capacitor 17 i.5 discharged
through a flash tube 24 by closing a synchronizing switch 23,
and therea~ter the terminal voltage of the main storage cap-
acitor decreases. Under these conditions, closed loops areformed by the oscillation control capacitor 26, the base-emitter
path of the control transistor 27, the synchronizing switch
23, the primary winding 22a and the charging resistor 25
during the time synchronizing switch 23 is closed. Accord-
ingly, the electric charge stored on the capacitor 26 is
also discharged through the above described closed loop, and
thereby a positive potential appears at the base 01ectrode
of the control transistor 27. By the positive potential,
the control transistor Z7 is rendered to be conductive. When
the control transistor 27 becomes conductive~ the oscillat-
ing transistor 13 is made non-conductive because the oscill-
ating capacitor 14 is short-circuited by the control trans
istor 27. By turning the oscillating transistor 13 OFF,
the oscillating operation of the oscillator circuit OC is
ceased, and thereby the current supply to the main storage
capacitor is stopped. When the oscillating operation of the
o.scillator circuit OC is stopped, the current from the direct
current power s~urce circuit A can be sufficiently supplied
to the second load circuit H by closing the switch 28 in
3ynchronizing with the synchronizing switch 23.
According to the power supply arrangement of Figure
2, the oscillating transistor 13 is turned OFF and the os-
- 13 -
~ 1~4~21
cillating operation of the oscillator circuit OC can also be
stopped by closing -the synchronizing switch 23 and thereby
can operate the second load equipment, even when the main
storage capacitor is not so fully charged, becau3e the os-
cillation control circuit G is provided between the voltage
converter circuit B and the trigger ~igna:L yenfrating cir-
cuit E.
Additionally, PNP type transistors can be used
instead of the transistors 13 and 27 in the above described
embodiment, in order to perform the same function as that of
the arrangement of Figure 2.
In the arrangements of Figures 1 and 2, the oscill-
ating operations are not perfectly stopped, in some cases, but
are slightly continued in spite of the fact that the transistor
27 operates, when, for example, the ambient temperature is
high. Since the voltage drop of the direct current power source
10, however, is very low in the slight oscillation of the
converter, the advantages de~cribed above can be fully obtained.
Figure 3 is illustrative of other ernbodiments of
th~ present invention, and a power supply arrangement com-
prises, similar to the arrangement of Figure 2, a direct
current power source circuit A ~or use of a pair of load
equipmentg 7 a voltage converter circuit B for converting a
direct current voltage to an alternating current voltage,
a rectifier circuit C for rectifying the alternating current
voltage ~rorn the voltage converter circuit B to a direct
current voltage, a charging circuit D for storing the elec-
tric energy to be supplied to a fir~t load equiprnent, a
trigger ~ignal generating circuit E for triggering the first
load equiprnent F and an oscillation control circuit G, said
power supply arrangement further comprises an oscillation
stop timing control and adju~tiny circuit I for adjusting the
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oscillation stop timing.
Specif.ically, an oscillation starting circuit OS
of the voltage converter circuit B comprises a resistor 15
of which one terminal is connected to a juncture Jl located
between a battery 10 and a primary wind:ing 12a of an oscill-
ating transformer 12, a third winding 12c of the -transformer
12, an oscillation control switch in the form of a switching
-- l~c~
4~2 1
control transistor 29 of which a collector elec-trode i~ a
juncture J2 of the third winding 12c and a ,secondary
winding 12b of the oscillating transformer 12, a biasiny
resistor 30 and a surge absorbiny capacitor 4~. An
emitter elec-trode of the tran.sistor 29 is conrlected to a
base elec-trode of an oscillating
~b
5 2 ~
transistor 13 and one terminal of an oscillating capacitor 1~,
and the resistor 30 is connected between -the collector electrode
and a base electrode of the transi3tor 29. ~he oscillatiorl
control circuit G comprises a voltage detecting element in the
form of a neon glow lamp 31 connected to the base electrode of
the tran~istor 29 and the re~i3tor 30 and an 03cillation control
capacitor 26 connected to the neon glow lamp 31 in parallel
relationship. ~he oscillation stop timing control circuit I
comprises a charging resistor 25 connected between a juncture
J3 and the neon glow lamp 31 and a voltage dividing variable
resistor 32 connected between a juncture J$ of the charging
resistor 25 and the neon glow lamp 31.
In the power supply arrangement, a zener diode and a
trigger diode may employed as the voltage detecting element in-
stead of the neon glow lamp 31. .,
In operation 3 when a power source switc~ 11 is closed,
the current initially flows from the battery 10 of the power
source circuit A by way of the resistor 15, the third winding
12c of the oscillating transformer 12, the resistor 30, the
oscillation control capacitor 26 and the variable re~istor 32,
and thereby the oscillation control transi3tor 29 is made con-
ductive. When the transistor 29 becomes conductive, current is
~upplied from the battery 10 by way of the resistor 15, the third
winding 12c and a collector-emitter path of the oscillation con-
trol transistor 29 to the oscillating capacitor 14. ~he oscil-
lating transi~t~r 13 becomes conductive due to the electric
charge of the capacitor 1~ and the o~cillator circuit OC co~-
mences the oscillating ope~ation. By the oscillating operation
of the os-illator circuit OC, a high alternating current voltage
is induced at the seconda:ry winding 12b of the oscillating
transformer 12~ The alternating current voltage i~ rectified
~y the diode 16 of the rectifier circuit C, and a direct-
- 15 -
"
current flows in a current loop for~(le~ by the secor~ ry ~,li.rlr3irlg~:L~
the collec-tor-emitte:r path of the txanfl:l.s10Y ~, a base-e(~litlif~r p,1l,h
o~ the tranf3if~lor 1~, -the ~nain ;;torage ca~jac:itor :ll and the tl.io~e l~
and, a-t -the sarne -tlmf3, l.n a current loo~ ~orrrled b~l secorldclry w:ind.i.ng
12b, the res:istjol ~(), -thf capacitor 26, thfi resi.f)-tor 25 arld the
diode 16. AccordirlgLy, -the rflairl sto.rage capaci.l;or :l/ arld the o-Jcl--
llation control capacitor 26 are, respectively, charged a-t -the
polarity as r3hown in h1igure ~. ~ur-ther, the electric charge is also
stored on a triggering capacitor 21 oY the tri~ger rJig~na].~erlera--
-ting circuit ~ by -the current f:Lowin~ by way o~ the dio~e~ 16, the
secondary winding 12b, the tranæif3tor 3S and 1.2, the rer;istor 33
the capacitor 21 and the resistor 20.
When the main r3torage capacitor 17 is charged up to the pre~
determined voltage, the neon glow lamp 31 in the osci.llation control
circuit G is ~ired by a voltage potentia:L in a closed loop :~ormed
by the main storage capacitor 17, the resistor 25, the neon glow
la~p 31 and the base electrode o~ the oscillation control transistor
29. In this case, lighting voltage of the neon glow larnp 31 is
appro~imately set to the maximum char~ing voltage o~ the lQGIin stor-
a~e capacitor lr/. When the neon glow larQp 31 ill~ninates, thenegative potential appears at the base elec-t:rode o~ the transistor
29, and thereby the transistor 29 is rendered cut-o~. When the
transistor 29 becomes non-conductive, the oscillating opera-tion
o~ the of~cillator circuit UC i S stopped, because the current is
~5 interrupte(l between the of3cillating trans~orMer ].2 and -the base
electrode o~ the o~)cilla-tirlg transistor :L~.
hrl clC tl~.'l'tiOrl v~ tag~e ol.' tihf3 rnain 3torage capaci-tor 1l can be
set, to r-~uch as, ~or example, ~0 volts, arl~l t;he secon~ary win-ling
:l.2b i.~, ln t,his caf3~, Sf3t; f.~o that the alternatlng currerlt; voltage
~J o~ 45~ voll;s :if.~ inducf3~ therf3~rorn. When the main s-torage capacitor
5 2 ~ .
17 is chclrged up to the preset voltage r-,uch as ths ~() VO1~ the
neon glow lamp ~1 ,iLlu~ninates and the or,~ci.l.Lator clrcllit (J~ ~to~J
it;s operation. When the oLJcillating oI)erat:k~n,i.s ces~L~ed, the ter
minal voltage of the rnain storage capacitoY gradl1e,lly decreases to
a given value such a,~.3, f.'or exarnple, ~2~ vo1tc" and then -!;he neon
glow larnp 31. ls exl;inguishe(l. When -th0 ne()rl glow 'I,arr~ L e~l;1,ng~ui-
shed, -the potential at the base e:l.ec-trode o~ the oscillati.on control
transistor 2g gradually increases, and the transistor 29 turns on.
When the transistor 29 becomes conductive, the base current is
supplied to the base electrode o e the oscil:Lati.ng trans.ir3to:r l3
from the battery lO -to make the transistor 13 ON, and. t;here'by the
oscillating operation is again started. 'l1he charging resistor 25
and the voltage dividing variable resistor 32 are employed for
setting the actuation voltage of the main storage capacitor 17.
~articularly, the charging maximum voltage of the Main storage
capacitor 17 is adjusted by the vol.tage divid.ing variable resistor
32. ~ioreeurther, the capacitor 26 activates the functions for
making the flickering action of the neon glow lamp 31 east and ~or
elimin.atin~ a voltage hysterisis of the .lamp 31 in flickering.
'~he maximurrl charging vol-tage o~' the alain stora~ oclpacitor 17
can be always set to the constant value, becau-e the neon glow 'Lamp
31 detects the charging voltage o~ the capacitor 17 an~ stops the
activation O-.e the volta~e converter circuit ~ a-t p.rede-termined
vol1,age~ value o~ the main sto,rage capaci~or Lr/ by con-trolling the
~N and OF1~ ope.ra-tionf3 ol' the control tran~istor 29. Accordingly,
thf3 or-~cillf.lting 1iransformer L~ oI' which ~secondary winding voltage
i,fl hi~h ~)llC~L ~IJ ~JO voLl,~,3rrla,l/ b~ u,cJed in order to rrlake charg,ing
tifne conL-3tant f3hort. l~'urt~le:r, a salal~ ca~pabili-l"y t:ranr)istor ~lay
'b~ U3ed ~lf:~ the control tranf;ifJtor 29.
ccording to t~lf3 L)o~1fr supLj:Ly arrang,~errlcnt, i.-t iS convenien-t
- 17 -
2 l
to take a picture continuou~31y, as well as the elf,'C tr:ic, fl.~,h d f`'`/iC*
is easy to opera-te, 3ince the charg.i.rl~ t:irae cons~l,ar)l, ~ f~Jnal.:L.
~'urther, the power supp:Ly aIrange~lent, ic.~ very c.,onl/erl:ient to o~errliJf
-the plurality of load e~uipment~-3, since the~ cha.r~in~S l;i~ae of the
rnain storage capa(itor of -the char~ing circlLl~ smal 1.
In view of the above~ it will be seen that the several obj f'C t,'-3
o~ the invention are achieved and other advantageous results at-tained.
2~
~()
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