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Gray code – Gray code Table

The Gray code is a special type of binary code that is unweighted (the digits that make up the code does not have an assigned weight).

What is Electrical Resistivity?

Electrical resistivity [ρ] (rho) is a characteristic of materials and has ohm-meter unit. Resistivity indicates how much the material opposes the flow of electric current.

Fire alarm circuit using thermostats and SCR

Fire alarm circuit using thermostats and SCR.

This circuit uses several thermostats in parallel for its operation. They can be as many as you want and must be placed in the places where you want to sense the temperature.

Power Failure alarm using transformer and relay

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.

Door opening monitor

Door opening monitor

The circuit allows detecting the opening of one or more doors with an audible and a visual warning.

3 Auto Shut off Battery Charger circuits (12V)

Why is an auto shut off battery charger needed? The main reason to get an auto shut off battery charger is to protect the battery from overcharging and consequently reducing its useful life….

Bike Flashing LED Lights Circuit

Bike Flashing LED Lights Circuit. If you’re a cycling fan, and you like biking, night and day, this useful circuit will make you to be visible and safe

12V Auto Turn-off Battery Charger with Current Limiter

12V Auto Turn-off Battery Charger

This 12V Auto Turn-off Battery Charger with current limiter, uses only 4 transistors, will stop charging the battery when it has 14 volts between its terminals and limits the charging current to a maximum of 2 amps.

How to Measure Beta of a Transistor?

How to Measure Beta of a Transistor? (β / hfe of transistor)

The beta (β) is a characteristic of each transistor. This feature is found in the NTE, ECG manuals, etc. These manuals have a minimum or approximate values of the real values. This means that we do not know the real value of the transistor.