firing circuit for SCR

i want to work with thyristor .please suggest some firing circuit for thyristor.

are you sure it's thyristors you're interested in? thyristors are for switching AC voltages.

You may want to use a MOSFET - these can switch DC. I recently used a N-channel MOSFET, a P30N06LE worked well for me... these can handle 30 amps at 60 volts with a proper heatsink! They only drop 1 volt across the source/drain which is quite nice.

Have a look on google for simple MOSFET circuits! there are millions


And if you DO want to switch AC voltage... use a triac

also if using a triac, also use a traic optocoupler. it isolates the electronics, and allows function even with uneven ac loads.