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ArcticMyst Security by Avery

my testload and new Fluke 115 !pic heavy!

Joined
Jul 4, 2008
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Alright, so I posted awhile ago about my new fluke and to be honest I screwed up the post and made a few people scratch their heads in confusion. Alright. So.
Here it goes.

Pic 1. I have my DMM set on DC volts.
Pic 2. This is my overly ugly soldering job. The test load works. NO 1W 1ohm resistors in Korea as a normal stock item... so I used 4x 1/4W 1 ohm for 1/2W 1ohm. I used silver solder as that is what I had at the time. I purposely overdid the solder to make test points for my DMM.

Pic3. Here I am testing the voltage and current mA across the load. Driver raw output delivers nearly 5.6VDC without the load of DMM. In this configuration with load the voltage drop across the load is 3.63 VDC. When I measure the current across the load on DC Amps I get 426.4mA.

Pic4. Voltage drop across dummy load.
Pic5. Using the resistor to get mV reading
Pic6. Measuring mA across entire dummy load.
Pic7. Measuring the mV across the test resistor.

- Not much in the way difference in readings. both methods settled to within 9-10mA of each other.
Dummy becomes extremely hot after about 20secs. Diodes get hot as well as the resistors.
 

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Benm

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Nice meter.. but how did you manage to get that solder on there? Looks like you just flicked it at the board from across the room with remarkable aim ;p

The diodes and resistors getting hot is normal. They are all rated for 1 amp in this configuration, but that rating is based on mounting with decent air flow - not packed together that closely. If you ran that at 1 amp for a while i wouldn't be entirely surprised if the middle diodes managed to desolder themselves... a trick they sometimes used in TV sets with resistors to prevent the whole thing catching fire.
 
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Actually I had some problems with the iron. it is fixed now.

Yes, it's crappy. I know.
 

Benm

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Good you managed to fix it... i once had a roll of solder that produced welds like those, i suppose they forgot the flux and/or got the metal ratios wrong.
 
Joined
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Nice meter.. but how did you manage to get that solder on there? Looks like you just flicked it at the board from across the room with remarkable aim ;p

This made me laugh much :D

I agree about the meter. I like it very much! :beer:
 




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