I have the following circuit connected, but when power is applied the transistors become excessively hot, in under 15 seconds. The 12V power source consists of two 6V lantern batteries in series. I belive that the voltage/current I'm using would be within the SOA for a single transistor, but I have two connected in parallel. I think that it may be a problem of the transistors not being turned completely on/off with the pulses of the 555, and instead only mostly off, leaving some resistance, which in turn leads to the heating. If anyone here could help me figure this out, I'd be very greatful.
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