.:madworm:.'s photos with the keyword: voltage

Testing the power supply that came with my LED strip. Made with gnuplot.

Still withing tolerances for 5V AVR chips. Lucky me! But I didn't have 'peak detect' turned on, so maybe there are some nasty spikes hidden in there. Better use a voltage regulator + 5.5V Zener diode in the future.

Now I'm absolutely certain that I will NOT use this to power any micorcontroller projects anymore without massive precautions. My AVR ATmega chips seem to have survived this treatment so far, but I will NOT power the ATxmega boards with this thing directly. This cries for an additional voltage regulator + Zener diode just in case. These spikes happen when turning on the output of the power supply (switched by relais). I haven't tested if any overshoot happens when pressing the voltage-increment buttons. It would be quite sad if changing the output by +-0.1V would create spikes.

This hopefully illustrates a bit where the 200Vpp were coming from, that made my fingers hurt. Only because of the bad GND connector... The symbols I've used may not be 100% correct ;-) Besides I don't care what kind of core the transformer has when I get zapped.

That wall-wart is a piece of crap. It claims to spit out 12V DC, capable of 500mA. I used my dummy-load to test it a bit. I had to pull close to 700mA out of it to make its output drop to 12V. It will go into the recycling bin right away. Fortuitously I found a switch-mode power supply that goes up to 15V. I'll use that one instead. As the wallwart only consisted of a transformer, rectifier diodes and a cap, all the battery charging logic must be in the car-jump-start device itself. Shouldn't be an issue.

There's a voltage drop of about 1V across the 5m strip. Too much resistance. Needs multiple power injections to compensate.

Initially I had put these bridge-pads on there to select which pins are + and - and connect capacitors to them. Today I used this board with an MCP1804-SOP23-5 voltage regulator. I had everything plugged in and was in need of another GND pin. Not just the one going to the chip, bot one going to the load. Thanks to these jumpers I could use the unused pin #5 (top row in the middle) and just bridge it to GND. I need more of these little moments!