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Chetan Bhargava
Chetan Bhargava
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We use the attached circuit for some diagnostic timing prior to doing experiments. Basically when the momentary switch is closed, from a location away from the generator box, the left side of C2 is pulled up to ground from ~-6V and C2 can discharge through the oscilloscope. The goal is to have a battery powered box driven by a switch that can close without bounce.

It seems like a p-channel mosfet could act as the switch if the gate is driven to -9V. That solves the switching, but not the debounce issue. I need the switch to close somewhat quickly, <1us, so an RC debounce doesn't seem to make the most sense. I have used monostable multivibrators before but couldn't find much about getting them to output something like the ~-9 volts I would need to drive the p channel mosfet. Are there any simple solutions that I've overlooked or would a different type of switch make more sense? Pulse Generator Thanks!

Mark

We use the attached circuit for some diagnostic timing prior to doing experiments. Basically when the momentary switch is closed, from a location away from the generator box, the left side of C2 is pulled up to ground from ~-6V and C2 can discharge through the oscilloscope. The goal is to have a battery powered box driven by a switch that can close without bounce.

It seems like a p-channel mosfet could act as the switch if the gate is driven to -9V. That solves the switching, but not the debounce issue. I need the switch to close somewhat quickly, <1us, so an RC debounce doesn't seem to make the most sense. I have used monostable multivibrators before but couldn't find much about getting them to output something like the ~-9 volts I would need to drive the p channel mosfet. Are there any simple solutions that I've overlooked or would a different type of switch make more sense? Pulse Generator Thanks!

Mark

We use the attached circuit for some diagnostic timing prior to doing experiments. Basically when the momentary switch is closed, from a location away from the generator box, the left side of C2 is pulled up to ground from ~-6V and C2 can discharge through the oscilloscope. The goal is to have a battery powered box driven by a switch that can close without bounce.

It seems like a p-channel mosfet could act as the switch if the gate is driven to -9V. That solves the switching, but not the debounce issue. I need the switch to close somewhat quickly, <1us, so an RC debounce doesn't seem to make the most sense. I have used monostable multivibrators before but couldn't find much about getting them to output something like the ~-9 volts I would need to drive the p channel mosfet. Are there any simple solutions that I've overlooked or would a different type of switch make more sense? Pulse Generator

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Mark
Mark
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Adding switch debounce to discharge circuit

We use the attached circuit for some diagnostic timing prior to doing experiments. Basically when the momentary switch is closed, from a location away from the generator box, the left side of C2 is pulled up to ground from ~-6V and C2 can discharge through the oscilloscope. The goal is to have a battery powered box driven by a switch that can close without bounce.

It seems like a p-channel mosfet could act as the switch if the gate is driven to -9V. That solves the switching, but not the debounce issue. I need the switch to close somewhat quickly, <1us, so an RC debounce doesn't seem to make the most sense. I have used monostable multivibrators before but couldn't find much about getting them to output something like the ~-9 volts I would need to drive the p channel mosfet. Are there any simple solutions that I've overlooked or would a different type of switch make more sense? Pulse Generator Thanks!

Mark