Voltage level
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Voltage level

by lightningserpent on Sat May 26, 2012 9:03 am

I have assembled the power section on the RC1a minus the 12v section. when i attach power to the board my volt meter reads ~4v, but when I push the power button the voltage drops to 0 and my power supply get hot. I've tried a couple different supplies. the meter seems to show everything is connected, but honestly I am lost. I cannot see any shorts on the board, and nothing gets hot(except for the power supply). I would appreciate any suggestions offered.
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Re: Voltage level

by viperspike on Sun May 27, 2012 3:41 pm

double check this before you start. But I would check

IC2
pin 5 to ground = power supply voltage
pin 1 to ground = 12VDC

IC1
pin 1 to ground = power supply voltage
pin 5 to ground = 6VDC

IC4
pin 2 = power supply voltage
pin 3 to ground = 24VDC

be careful not to short those pins on the IC together when shooting for voltage. you could also move over to the diodes it that makes it easier. I hooked up my new avr programmer and actually programmed my WB2010 ver2b with the Programmer set to 5vdb. But when i pressed the power button with the avr programmer hooked up, it smoked IC1 for me. Now instead of 3.3VDC I get about 4VDC. you might have smoked one of the power IC's causing your problems. I would start there if it were me, the closer to when the power is actually generated, the more components you eliminate from the possibilities. - Viperspike
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Re: Voltage level

by lightningserpent on Sun May 27, 2012 5:27 pm

every IC reads 0v, my power supply readout drops to 0v when the wave bubble is turned on. I am going to reorder the IC's, and go from there (i ordered multiple 3v3's but singles on the others). Thank you for this information. I will be more prepared on my next go.
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Re: Voltage level

by evilroot on Tue May 29, 2012 1:15 am

I rather doubt the problem is with the chips themselves. It sounds like you have either a bridged connection, wrong component placed, chip backwards, or other issue that is causing a short somewhere down the line. That your power supply output drops to 0 when you switch the device on is a dead giveaway that there's a serious short somewhere, check and double-check your work and find it!
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Re: Voltage level

by lightningserpent on Thu May 31, 2012 5:47 pm

Reattached the new IC's and inductors (they dont remove very well). Voltages check out...almost. IC1 and IC2 check out perfectly (3.27 and 5.1). IC4 pin2 reads input voltage as it should and pin three also matches input voltage. however when I read at the cap I get 21.2v. Then I realized i had an 820k resistor on R7. I had an old 1.0M from another project i was going to replace the 820k with the 1M, but when i check the resistor with my meter it read over limit, even on the 20M setting. I will order a 1M resistor with my next batch of parts. Hopefully that will get me up to 28v. Thanks for your help.
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