Sunday, June 15, 2014
That way battery banks can be charged, electroplating can be done, current and voltage can be controlled with opamps, thyristors are very rugged compared to transistors and MOSFETS in that order.
Edit the circuit eagle cad file del00015.zip,
Wednesday, October 15, 2008
A Center tap 50Hz Step Down Transformer with two diodes is used to get a train of Positive Sine Pulses at 100Hz which is applied to Q6 base via R51. 2N2646 is a unijunction transistor(UJT) in a TO-18 metal package. The control voltage or voltage proportional to error is fed to R56-Q3, The UJT drives a pulse transformer which provides isolation from the Load which the SCR bridge is controlling. This phase angle control gives a near Linear closed loop control for a SCR bridge which may be used in Electroplating or a Preregulator of a big power supply.