AFIK, there are some issues on fast triac switching like dv/dt which could turn on the triac without any gate command. So the load characteristics it's important (it's resistive or inductive?). On old TV the 16KHz horizontal deflection use two thyristors just to prevent this problem but the voltage was huge compared with your application. The question is why use triac at 50V and 50KHz switching (assuming you're not switching 100 A) ? The reason of using a triac is automatic turn off at lowest A1-A2 current than holding current and bidirectional current conducting. Using two MOS FET's will do the probably same like a triac without those problems. On 4/22/07, Peter P. wrote: > Hi all, > > can a triac be used to switch a higher frequency signal ? By this I mean > asynchronous, on/off switching, probably with DC drive on the gate. Basically is > there anything that prevents a triac from turning off properly when its A1-A2 > see maybe 50kHz and 50Vpp ? Power electronics texts yield no clues and triac > manufacturers likely don't test for this at all. I am aware of horizontal > deflection circuits in TV implemented with thyristors (of somewhat special > make), but this is different, I will switch the triacs at a much lower frequency > than the 'power' input. > > thanks for any pointers, > Peter P. > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist