12V wall wart down to 5V
5227
When would I use a voltage regulator vs voltage divider?
67432
Can connecting of AC adaptor first into device, then into mains pose a risk of voltage spike?
132950
Scale 30-50 mV signal to 0-5 V range
60265
Why do I only have 30V going to my light fixture
10700
How to get more than 100mA from a USB port
30624
Automatically switching from battery to DC wall adapter on insertion
37100
Using a higher current charger on a laptop which requires a lower current
80449
DIY 24v to 5v usb phone charger
87183
Passive POE: Need 5V @ 2A at the destination
129553
5V to 3.3V Level shifting circuit
134229
Powering a WS2812B strip
66305
Getting rid of AC/DC adapters
125118
230V AC to 5V DC converter, lossless
141150
Undervolting PC Fan from 12V to 7V
131875
Convert line voltage heating system to use low voltage thermostats
92911
Unexpected voltage with switch turned off
59547
Short circuit = zero voltage?