5.5.3. Electric circuit of the control unit
Electric circuit of the control unit is shown on the Figure 7.
The control unit is purposed for all necessary connections and stabilizing of the motor rotation speed.
Electric circuit of the control unit consists of several units: rotation speed stabilization unit, voltage converter unit, scalers unit
(purposed for film counting), and some other units purposed for controlling of the camera.
5.5.3.1. Board of the voltage converter and stabilizers U1
The board U1 contains voltage stabilizers of 5V and 12.6V; transformer with rectifier; parametrical stabilizers of –27V and –
12.6V.
The stabilizer of 5V is built using VR diode D1 (2S168A) and output transistor T1 (2T909A).
Resistor R3 sets a required voltage on the stabilizer output. The 5V voltage is required for powering logic elements of the
scaler.
The stabilizer 12.6V is built on the transistor T2 (2T312B), IC Y1 (140UD1B), stabilitrons D2, D3 (D818E, D814A) and
transistor T9 (2T909A) mounted off the board.
The IC Y1 is included into feedback chain. Voltage on the inverting input of the operational amplifier is stabilized by stabilitron
D2. Required voltage on the output of the stabilizers is set by means of the trimming resistor R5.
Output voltage of the operational amplifier controls operation of the output transistor T9 through transistor T2. Diode D3
matches signal levels of the transistor T2 and IC Y1.
The voltage converter is used to provide –12.6V and –27V using +27V. The converter is built as duple multivibrator on the
transistors T4, T5 (MP26B) and transformer Tr. Output secondary voltage is rectified by half-duplex rectifier built on diodes
D4-D7 (2D522B). Voltage stabilizer of –12.6V and –27V is built on stabilitronts D8-D10 (D814D).
5.5.3.2. Board of the scalers U2
Scalers board is purposed for producing of the footage reading impulses. Is also produces impulses after every 10
th
and 100
th
frame.
The camera sensor impulses are passed from the board U4 to the pin 1 of the connector III5 and further to the IC U1
(134LB1A) for improving of the impulse fronts.
Triggers Y2-1 and Y2-2 (IC 134TB14) form a scaler dividing a frequency by 4. This provides matching of the camera sensor
impulses with quantity of exposed frames.
Triggers Y3-1, Y3-2, Y4-1, Y4-2, Y5-1, Y5-2 and Y6-1 extract every 50
th
impulse to read meters of the exposed film.
A signal from pin 8 of the trigger Y6-1 passes to the NOR gate Y7-4 and further to the differentiating circuit Y12-1, Y12-2.
Differentiated signal passes to the IC Y10-2 for improving a fronts, and further to the inflowing currents producer Y11 (IC
146AA2A). The signal for pin 12 of the IC Y11 passes to the film counter of the remote control unit.
Trigger Y6-2 is purposed for extracting every 100
th
frame. The impulses of every 10
th
and every 100
th
frame are passed through
the coincidence elements (Y7-Y8 and Y10-3) to the inflowing currents producer Y13, and from the pin 12 of the connector III8
to the remote control unit to register the feedback impulse on the external equipment. ICs Y8, Y10 and Y11 are used to place an
‘events’ mark on the film.
When switch B4 ‘MARK’ is set to ‘MARK’ position, signals form the buttons ‘events’ of the remote control unit and control
unit pass to the input of the IC Y9-4, and to the inflowing currents producer Y11 through the matching logic element Y10-1.
From the UC Y11 the signal passes to the camera LEDs (through the pin 9 of the connector III2) to mark a film.
It this position of the switch B4 ‘MARK’ a signal also appears on the LEDs at every 10
th
and 100
th
frame.
In the position ‘SOWING’ of the switch B4 ‘ MARK’, external signals are supplied to the LEDs.
5.5.3.3. Board of the DC amplifier U3 and Board of connections U4
DC amplifier (board U3) is purposed for providing a master voltage supplied to the power amplifier built on transistors T1-T8.
The amplifier works as described below.
When you switch on the switch B1 ‘POWER’ of the control unit, stabilized voltage 12.6V is supplied to the board through pin
11 of the connector III6. Reference voltage from scaler R11-R14 is filtered by capacitor C5 and passed to the inverting input of
the operational amplifier (IC Y2, 140UD1B). Then it is amplified and supplied to emitter follower built on transistor T5
(2T608B). Then it is passed to the output stage of the power amplifier.
It the ‘START’ mode, the output stage is open, and provides a power to the camera motor through pins 19-24 of the connector
III2. A tachogenerator linked to the motor begin to run together with the motor. The TG voltage is passed to the commutation
board U4 of the control unit.
Depending on the selected shooting speed (set by selector B3 ‘FPS’), one of the relays P1-P6 in actuated and passes the
feedback voltage from the TG to the operational amplifier (Y1) and transistors T1-T3 of the board U3. Output voltage of the
transistor T3 has inverted polarity relatively to reference voltage. Operational amplifier (IC Y2) of the board U3 combines the
reference voltage and negative feedback voltage.
The motor will speed up until feedback voltage match the reference voltage. Sustained speed will be maintained automatically.
Board U4 contains also commutation device of the ‘START’ mode.
Summary of Contents for GLADIOLUS
Page 6: ...Figure 2 Kinematics ...
