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Ramp and Pedestal Triggering Circuit Diagram
The circuit for ramp and pedestal triggering of two SCR’s connected in antiparallel for controlling power in an AC load. This circuit, R acts as a potential divider. Wiper (pot) R controls the value of pedestal voltage.
The diodes allows the capacitor C to be quickly charged to V through the low resistance of the upper portion of R.
Ramp and Pedestal Triggering Circuit Diagram
The position wiper (Pot) on R always setting the voltage v is less than the UJT firing voltage .
When the wiper setting is such that is small, the voltage V charges the capacitor Vc reaches and UJT starts conduction.
A pulse produced at the primary as well as at secondaries of the transformer due to discharging of capacitor through UJT and primary of the pulse transformer.
Hi
Sir, i need help on spot welding circuit,I come accross the ramp/pedestal trigger circuit on your site .
How best can it be modified into pot welding by connecting a 380vac transfomer and a foot switch.
Regards
Michael