ONE TRANSISTOR AUDIO MIXER

A constant-current/constant-voltage linear charger for single-cell lithium-ion (Li-ion) batteries can be constructed using the EUP8054 battery charger controller chip and a few passive components. This compact integrated circuit is suitable for various portable devices and is compatible with USB...

The original input data describes a common situation in many companies where a single type of telephone is purchased for all employees. This is often done to take advantage of quantity discounts. However, this can lead to problems as the...

This is a simple transistor-based burglar alarm circuit. Its features include automatic exit and entry delays, along with a timed bell cut-off and reset. It is designed to be used with common types of normally-closed input devices such as...

The interval between rings can be adjusted by changing the value of the 1 Meg resistor. A 70 volt, 30 Hz ringing voltage is generated from the 120 volt side of a small 12.6 VAC power transformer (Radio Shack...

The prototype circuit successfully addresses the charging issue. It employs two voltage dividers to supply 2.0V to D- and 2.8V to another component. The circuit design features two voltage dividers, which are essential for providing specific voltage levels to...

This crystal set has been designed to incorporate features from previous radio models. The #62 radio merges the single-piece design of the #48 set with the dual detector functionality of more recent models. It utilizes a dual honeycomb coil...