So I built this h-bridge driver for a solenoid valve, and it worked beautifully for a while.
After my third circuit, suddenly things went boom and magic smoke came out of the p-fets (and sometimes of the n-fets too)... I don't know what changed. Maybe I've been lucky and the circuit's been working on the transistors' tolerance thresholds until now.
My take is that for a brief moment M1 and M4 (or M2 and M3) are short-circuited and that's why things are burning up ... I can find no other reason.
CW and CCW are 0 to 5V signals, btw. Zeners are rated at 18V.
What am I doing wrong? Is there a way to add simple parts to it so as to somehow de-phase M4 and M1 (and M3 and M2) when they're triggered on/off so that they'll never short circuit?
I was thinking of placing a diode and a cap and resistor in series in inverse parallel at each transistor's gate to delay their turn-on time whilst keeping their turn off time almost unaffected.
Something like this:
Is this a good idea? Anyone have a better one, without requiring that each transistor be switched individually?
After my third circuit, suddenly things went boom and magic smoke came out of the p-fets (and sometimes of the n-fets too)... I don't know what changed. Maybe I've been lucky and the circuit's been working on the transistors' tolerance thresholds until now.
My take is that for a brief moment M1 and M4 (or M2 and M3) are short-circuited and that's why things are burning up ... I can find no other reason.
CW and CCW are 0 to 5V signals, btw. Zeners are rated at 18V.
What am I doing wrong? Is there a way to add simple parts to it so as to somehow de-phase M4 and M1 (and M3 and M2) when they're triggered on/off so that they'll never short circuit?
I was thinking of placing a diode and a cap and resistor in series in inverse parallel at each transistor's gate to delay their turn-on time whilst keeping their turn off time almost unaffected.
Something like this:
Is this a good idea? Anyone have a better one, without requiring that each transistor be switched individually?
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