A Firing Circuit is used
to turn on a thyristor. Firing Circuits can be built using different components.
Some of them are:
(1) Firing Circuit using
UJT & Pulse Transformer.
(2) Firing Circuits using Operational Amplifiers
(3) Digital Firing Circuits
DESCRIPTION OF THE CIRCUIT
The Circuit which is drawn
is an 8 bit Digital Firing Circuit. This circuit is constructed using 6
(1) The circuit contains two 74LS193 ICs which is an up / down counter. In this circuit its used as a
(2) There are two 74LS32 ICs which are Quad OR Gates.
(3) The Clock to the circuit is provided by 555 Timer IC.
(4) MOC 3020 is an opto Triac. This IC is providing Isolation to the triac.