I prototyped a quick circuit like this one. I just connected a 5V DC supply through a 1K resistor to turn the FETs on and off. The output of the FETs are connected through a 25W light bulb to a 120VAC source.
The circuit works in that turning the 5V source on turns the bulb on and jumpering the gate side of the 1K resistor to the negative side turns it off except it only turns one of the FETs off. I presume only one is being turned off because my scope shows one half of a sine wave.
So I'm thinking that either jumpering that resistor isn't sufficient to turn both off or I have a bad FET. Correct?
If I have a bad FET, and it's the positive going part of the sine wave, can someone tell me how to tell which FET is bad?
EDIT: Perhaps answering my own question. The gate to source voltage is listed as +-20V so I'm trying to drive it with a logic level of 5V and perhaps that's the problem? If so, why does one FET turn off?
The circuit works in that turning the 5V source on turns the bulb on and jumpering the gate side of the 1K resistor to the negative side turns it off except it only turns one of the FETs off. I presume only one is being turned off because my scope shows one half of a sine wave.
So I'm thinking that either jumpering that resistor isn't sufficient to turn both off or I have a bad FET. Correct?
If I have a bad FET, and it's the positive going part of the sine wave, can someone tell me how to tell which FET is bad?
EDIT: Perhaps answering my own question. The gate to source voltage is listed as +-20V so I'm trying to drive it with a logic level of 5V and perhaps that's the problem? If so, why does one FET turn off?
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