The old Panasonic NV-M5 has the standard for the time CRT based viewfinder assembly, which will happily take a composite video signal from an external source. This viewfinder has many more connections than I would have expected, as it has an input for the iris signal, which places a
Here’s a useful tool for testing both power supplies & batteries, a dummy load. This unit is rated up to 60W, at voltages from 1v to 25v, current from 200mA to 9.99A. This device requires a 12v DC power source separate from the load itself, to power the logic circuitry.
Here is a ZyXel WAP3205 WiFi Access Point that has suffered a reverse polarity event, due to an incorrect power supply being used with the unit. While most electronic gadgets are protected against reverse polarity with a blocking diode, this unit certainly wasn’t. Applying +12v DC the wrong way round