LED/Small Motor Tester/Evaluator Accessories
As invaluable as the Tester/Evaluator has been, in the case of animated models, it's somewhat awkward to use when I need to test devices that require the polarity to be reversible, or those that are triggered by a pushbutton. So, I built two accessories to do just that: The Reverser and The Trigger. Both units have banana plugs to connect it directly to the Tester/Evaluator.
The Reverser (below left) does just what the name implies: it reverses the polarity of the supply. It also has three LED pilot lights to a) confirm it has power, and b) confirm when the polarity matches that of the supply or is reversed. The toggle switch is a center-off type to kill the output; thus it also serves as a simple on-off control.
The Trigger (above right) utilizes a pushbutton to send a pulse of power. It has LED indicators to a) confirm it has power, and b) confirm when the button is pressed. It also has an on/off switch to disable the unit. Plus, it has a third output that delivers uninterrupted power to devices that operate on the "windshield wiper" principle—that is, the trigger starts the device, but it continues to run on its own until a limit switch stops it (self-indexing).