UJT or Unijunction transistor
The UJT or Unijunction transistor is constituted by two polluted regions, with three external terminals: two bases and one emitter.
Power failure alarm using transformer and relay
This power failure alarm circuit is very simple and is very useful when used with electric ovens, a refrigeration systems or to prevent a thief from cutting off the electrical power because it immediately warns of the problem. It also serves you when the fuses have blown.
This Electric Current Flow Indicator gives a visual indication that there is a current flow. Possible applications for this small circuit may be: a battery charger, a voltage power source, etc.
In order to achieve our objective we place 3 rectifier diodes in series, which in turn are in series with the load / battery.