Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Having issues with my power supply

Status
Not open for further replies.
O built a power supply several months ago and it worked fine. It measured all the right voltages at the correct spot. But now when I went to go and fix some of the wires connected to the pretentsheomiter that got diconnected. Then all the sudden the resistor starts to smoke for some reason. I am very confused by this and would like some other ideas on why.
 
Welcome, Zackary,

The reason that resistors smoke is that you exceed the power dissipation rating of the resistor! Heating of a resistor is (more-or-less) proportional to the power dissipated there-in. Resistors have power ratings, like 1/4W for a small film resistor up to 10s of W for large cement or wire-wound resistors. Pots are usually 1W or less.

What did you smoke? Post a schematic and indicate which resistor got hot.
 
well this was a school project, and I probably can't find the schematic again. But I can tell you that there is one resistor in the circuit [a 90Ω 5% restistor]. I
 
At 12 V across it, that resistor should be at least 2 W, 4 W or more would be better. The resistor should be labeled. Assuming it has leads, it should be the diameter of a pencil or larger.

My concern focuses on your problem statement. Namely, that the power supply worked fine until you "fixed" wires attached to the potentiometer. That is where I would look for problems, and without knowing what the potentiometer does or how the wires are attached to it we will all be at a loss.
 
Last year was my first year, so I was looking over my work again for improvements and I replaced a short wire and got a longer to replace. But it was only one wire though. I'll give you a picture towmorrowwhen I get into the shop.
 
But, did you actually alter the circuit, right?
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top