SPEED CONTROL OF DC MOTOR USING THYRISTOR TRIGGERING. MODEL IBL-PE-26

This trainer is intended to study the speed control of DC Motor using Thyristor Triggering. Using this trainer, it is possible study and observes waveforms at different points of circuit, during study. Additional equipment like a Dual Beam

Oscilloscope of 15MHz is required for observation of waveforms. This trainer consists of the following facilities.

a. Speed adjustment potentiometer,
b. Signal conditioning circuit,
c. Pulse triggering circuit,
d. Pulse transformer kit,
e. Power driver circuit using thyristors, a PMDC Motor,
f. Built-in Digital RPM indicator, and
g. Necessary power supplies.

Specifications:
? PMDC motor operating at 40V DC mounted on a stand and securely fastened.
? Maximum SPEED of the motor is 1440 RPM.
? Built-in Digital RPM indicator to observer the motor speed.
? Built in power supplies.

The test points include observation of the following:
a) Adjustable speed control voltage in the range of 0 to 5V DC.
b) Waveforms to observe RAMP generator
c) Trigger waveform produced by the triggering circuit
d) Transformed pulse output
e) GATE triggering of G1 and G2,
f) Anode and Cathode points of SCRs.

Thyristor:
The Thyristor used works on CLIP ASSEMBLY technology with
a) An average ON-State current of 10A @ 180? conduction angle.
b) Critical rate of rise of on-state current 50 A/ ?sec.
c) Peak gate current with 4A.
d) Average gate power dissipation 1 Watt.
e) Maximum peak reverse gate voltage 5 V.
f) Threshold voltage 0.77V.
g) Average gate power dissipation 1Watt.

Uni-Junction Transistor (UJT) specifications:
(Maximum ratings):
a) Base 1 ? Emitter voltage 30V,
b) Base 2 ? Emitter voltage 30V,
c) RMS Emitter current 50mA,
d) Emitter peak current 2A,
e) Total Power dissipation 300Mw