I've been working on a project for some time that has to have a digital control over what is baselined a potentiometer. The potentiometer is a simple 25 kOhm pot installed in an electric heat gun. Investigating the circuit, I now believe it is an AC circuit which contributing to the problem.
My first attempt with this has been to replace the potentiometer with a digital potentiometer. I tried two different digital pots thus far:
Microchip MCP42050 and 4131-103. I had the circuit functioning at one point with the MCP42050 but only briefly before it stopped functioning. Then I had to move and when I tried to rebuild with a replacement digital pot, I could never get it to work again. I'm driving the digital pots with an Arduino board. Thus far, I've fried 3-4 of arduinos and digital pots.
I'm thinking te AC heat gun is putting out quite a bit of power (even in the pot circuit) and I'm convinced its AC. Is there a better approach to this problem? Some kind of digital switch? I've played around with the idea of using a servo to drive the analog pot, but that seems inaccurate and like cheating.
FYI, the other half of this circuit uses a touchless infrared sensor and the arduino functions as a PID controller brain to regulate the heat gun and hold a specific heating profile over a time period.
P.S. tonight I rebuilt the circuit with the Microchip 4131-103 and actually got sparks to fly when I plugged it in with the heat gun, which is both exciting and makes me feel like a nincompoop. Prior to tonight it was just stinky, fried ICs.
My first attempt with this has been to replace the potentiometer with a digital potentiometer. I tried two different digital pots thus far:
Microchip MCP42050 and 4131-103. I had the circuit functioning at one point with the MCP42050 but only briefly before it stopped functioning. Then I had to move and when I tried to rebuild with a replacement digital pot, I could never get it to work again. I'm driving the digital pots with an Arduino board. Thus far, I've fried 3-4 of arduinos and digital pots.
I'm thinking te AC heat gun is putting out quite a bit of power (even in the pot circuit) and I'm convinced its AC. Is there a better approach to this problem? Some kind of digital switch? I've played around with the idea of using a servo to drive the analog pot, but that seems inaccurate and like cheating.
FYI, the other half of this circuit uses a touchless infrared sensor and the arduino functions as a PID controller brain to regulate the heat gun and hold a specific heating profile over a time period.
P.S. tonight I rebuilt the circuit with the Microchip 4131-103 and actually got sparks to fly when I plugged it in with the heat gun, which is both exciting and makes me feel like a nincompoop. Prior to tonight it was just stinky, fried ICs.
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