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Road Rage 2019 help with odd voltages

Started by selatape, January 13, 2020, 10:04:31 PM

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selatape

Hi everyone,

Just built the 2019 version of the road rage with an LT1054 and 78L15 15v regulator for my prototyping board and I think my voltages might be a bit off.

With no load I'm getting:
+9.0v (unregulated +9v output)
+8.8v (regulated +9v output)
+13v (between D3 and D4)
+16.2v (+15v output)
+16.9v (+18v output)
-8.8v (-9v output)

My first thought is to swap the regulator out but any other ideas if/where I should start troubleshooting? I remove the regulator presumably I should get +/-18v if everything else is working? Though I would ask before I start ripping apart the circuit.

Thanks for you help.

Update: I went ahead and removed the regulator and now I get +17.5V (+18v output). Seems a bit more like it. Never heard of problems with regulators, but I'm going to breadbaord a few to check.


selatape

Feel pretty daft but I had the regulator the wrong way round. The blame lies squarely on the bad datasheet for this one, if it's the bottom view of a TO-92, write it next to the pin configuration so numpties like me will see it ;D.

I'm still getting just +16.9v from the "+18v output" when using the 15v regulator, if anyone else has built this, is that as good as I'm likely to get?

franblanc

ROAD RAGE 2019: I'm also getting 16.8 volts from the 18 volts output pads. I have 9.2 volts running into the charge pump from a DC PSU. I have C5 and C6 omitted on the Road Rage with C6 jumpered between positive and negative. I reflowed everything and checked all the grounds. Not sure where I lost that extra volt but I need it to kick start a Univibe clone. Do you have the correct voltage readings for the LT1054 pins? Maybe I have a bad IC.