Twisted Sounds 8.5k

[mnhiphop101]

Is it normal for these to heat up to 160°f idling

 

[mnhiphop101]

Here's a pic with my handheld scope

 

[Perry Babin]

Was the black probe on the negative rail?

Where is the ground reference for the displayed waveform?

 

[mnhiphop101]

2ndary ground

 

[Perry Babin]

Set to DC coupling and place the black probe on the negative rail.

Everything on this IC is referenced to the negative rail except the high-side circuit (3 terminals).

 

[mnhiphop101]

3vdc squarewave

 

[Perry Babin]

Photo of the waveform?

Why was the waveform so much different on your other scope?

 

[mnhiphop101]

Idk. I was hoping u could tell me that.

 

[Perry Babin]

I think that drive signal is OK. It has an amplitude of about 7v.

Does your other scope show a square wave (perfectly square) when looking at the signal out of the PS driver IC?

 

[mnhiphop101]

Not really

 

[Perry Babin]

That looks like the probe needs calibration.

 

[mnhiphop101]

I'm gonna go off of what the hand held scope displayed. So why, when I put the fets in is there no switching?

 

[Perry Babin]

Did you try adjusting the probe?

Install the FETs and when there is no drive what is the DC voltage on the output of the LM211?

 

[mnhiphop101]

When I touch it to the test wave it looks perfect

 

[mnhiphop101]

Am I supposed to leave the 10k resistor in for this?

 

[Perry Babin]

The 10k is only necessary when there is no feedback, like when the outputs are out of the circuit.

Do you have another probe?

 

[mnhiphop101]

Ok

 

[mnhiphop101]

Is this referenced to negative rail?

 

[mnhiphop101]

Yes the wave looks the same with both probes

 

[Perry Babin]

Try adjusting it on the drive signal of the PS driver IC to see if it looks better on the waveforms in the output section.