Author: psu

Auto Switch-Off Power Supply (Variable Output 3.7V to 8.7V)

Auto Switch-Off Power Supply (Variable Output 3.7V to 8.7V)
Here is the auto switch-off power supply which will turn off itself when there is no load on the output. The output voltage can be vary from 3.7V upto 8.7V. Although this circuit uses fixed-voltage regulator LM7805, but its output voltage is adjustable, thanks to a potentiometer installed between common terminal of regulator IC and ground. For every 100-ohm increment in the in-circuit value of the resistance of potentiometer VR1, the output voltage increases by 1 volt. Thus, the

High Voltage, Low Current Power Supply (2000VDC from 15VDC)

High Voltage, Low Current Power Supply (2000VDC from 15VDC)
This is a high voltage, low current power supply capable to deliver 2000VDC output from 15VDC input voltage. It uses the combination of simple step-up transformer and Cockroft-Walton voltage multiplier circuit. Power supply with very high output voltage is a very useful source that can be effectively used in many applications like biasing of gas-discharge tubes and radiation detectors, etc. Such a power supply could also be used for protection of property by charging of fences. Here the current

15V 1A Regulated Symmetrical Power Supply

15V 1A Regulated Symmetrical Power Supply
This is the easy built 15V 1A regulated symmetrical power supply capable to deliver stabilized voltage of +15V DC and -15VDC. The maximum current output is about 1 ampere up to 1.5 ampere refer to the datasheet. The circuit uses IC regulator LM7815 for positive voltage and LM7915 for negative voltage. To obtain different voltage output, just replace the IC regulator LM78xx and LM79xx, the xx code is the output DC voltage value. (more…)

12V / 3A Regulated Power Supply

12V / 3A Regulated Power Supply
Here we provide a powerful 12V / 3A regulated power supply circuit. Of course the circuit provides a 12V regulated power supply with output current up to 3 amperes. It is specially designed for use with 2m handheld rigs with linear power amplifier and CB portable QRP rigs. The power supply circuit uses monolithic IC CA3085 voltage regulator in 8-lead TO-5 package. Its salient features include good load and line regulation, output current up to 100mA (which can be

How To Repair Computer Power Supply

How To Repair Computer Power Supply
If the power supply is damaged or does not work, the computer also will not be able to work. Before starting to repair computer power supply, we have to identify the cause of the damage. Damage to the power supply is usually caused due to three factors, it could be due to unstable voltage, excessive load, and it could also be due to the less good grounding system. To find out, we have to do the testing first to

Self Powered Battery Tester

Self Powered Battery Tester
This self powered battery tester circuit runs a fast battery test without the need of power supply or expensive moving-coil voltmeters. It features two ranges: when SW1 is set as shown in the schematic diagram, the device can test 3V to 15V batteries. When SW1 is switched to the other position, only 1.5V cells can be tested. (more…)

Versatile AA-Cell Battery Charger

Versatile AA-Cell Battery Charger
This is the circuit design of AA-Cell battery charger that can be used to charge six AA batteries at once. An integrated circuit of LM317 voltage regulator is configured as a constant-current source. It is used to supply the 50 mA charging current to S01-S06, an array of AA-cell battery holders. Each of the battery holders is wired in series with an LED and its associated shunt resistor. (more…)

Isolated Feedback SMPS 5VDC 1.5A

Isolated Feedback SMPS 5VDC 1.5A
Above schematic design is an isolated feedback SMPS (switched mode power supply) circuit using the isolated feedback capabilities of the TL3103 for both current and voltage sensing. This powersupply is powered from the AC mains and has an output of 5V DC at 1.5A. Both output voltage and current are sensed and the error voltages are applied to the error amplifiers of the TL594 PWM control IC. The 24V transformer has the output about 35V at the 1000uF filter