Detects if a device is not properly connected to its supplySuitable for battery chargers, portable appliance supplies etc. The above circuit can be useful to detect if the load of any battery charger or plug-in adapter supply is not properly connected. The load can be a set of batteries to be charged or any other [...]
The circuit in the figure derives its power from a USB port and produces 5 and 3.3V supply rails for portable devices, such as digital cameras, MP3 players, and PDAs. The circuit allows the port to maintain communications while, for example, charging a lithium-ion battery. IC2 boosts the battery voltage, VBATT, to 5V, and IC3 [...]
The converter uses no filters and is thus pretty broadbanded. All selectivity is trusted to the DB6NT converter and the Yaesu radio. The power supply is regulated by a three terminal voltage regulator, so the frequency won’t shift with input voltage fluctuations. The converter applies 13.8V to the coax line going to the antenna-mounted converter, [...]
12Vdc to 9,7.5,6 Vdc circuit This simple converter using a Zener diode and a transistor into a 9V DC 12V DC battery power to the maximum 1A. The circuit is very simple to build, and requires only 3 electronic components, resistors, zener diodes and transistors. The 2N3055 transistors, 1N4738A Zener diode or Zener voltage and the [...]
120 VAC Lamp Dimmer The full wave phase control circuit below was found in a RCA power circuits book from 1969. The load is placed in series with the AC line and the four diodes provide a full wave rectified voltage to the anode of a SCR. Two small signal transistors are connected in a [...]
The work of the power supply is the gain of 2N3053 2N3906 and 2N3904 is fixed internally at 2Watts. 2W switch power supply circuit It is to compensate the reduction of output power due to low voltage supply the transistor uses the Bridge-Tied-Load principle (BTL) which can provide an output of around 1.5 to 2 [...]
LM317 Variable Power Supply Regulator A circuit is timeless. LM317 regulator is a versatile and highly efficient 1.2-37V voltage can provide up to 1.5 Amps. of current with a large heat sink. It is ideal for almost any application. This was my first power source workbench and I still use it. Since LM317 is protected [...]
