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

Electric Car Battery Charger

Electric Car Battery Charger
This is the scheme diagram of electric car battery charger. As shown the circuit is a conventional power supply, followed by a regulator LM338 which is controlled by an operational amplifier which is responsible for controlling the state of charge to detect the precise moment that must stop and actuate the LED indicator. The resistive divider enables three stages, first take the reference voltage for the operational amplifier and, on the other, control the regulator LM338 through the output

Bench Power Supply Adjustable 1.25V-15V and Fix 5V

Bench Power Supply Adjustable 1.25V-15V and Fix 5V
This is bench Power Supply give you three types of voltage output that are adjustable 1.25V-15V / 1A positive voltage, adjustable 1.25V-15V / 1A negative voltage and Fix 5V 3A positive voltage. The regulator circuit in this bench Power Supply consists of a LM-317 integrated circuit. This IC is specially designed to perform the regulation function. Figure 6 shows a simplified circuit of how the LM-317 IC works. (more…)

0-30V / 5A Adjustable Symmetrical Power Supply

0-30V / 5A Adjustable Symmetrical Power Supply
In the scheme diagram below we present a 0-30V / 5A adjustable symmetrical power supply that can cover a wide range of applications for laboratory or workshop. Values ​​are included in the design diagram. The potentiometers P1 and P2 used to adjust each regulator output independently to the desired value in the range of 0 to 30V. C5 and C6 of 47 to 100nF capacitors improve the response regulators against switching transients at the output. (more…)

12V DC Power Supply without Transformer

12V DC Power Supply without Transformer
These are 12V DC power supply circuit which designed without transformer (trafo). These circuit use capacitive reactance instead of resistance; and it doesn't generate very much heat.The circuit draws about 30ma AC. Always use a fuse and/or a fusible resistor to be on the safe side. The values given are only a guide. There should be more than enough power available for timers, light operated switches, temperature controllers etc, provided that you use an optical isolator as your circuit's

1.2V – 57V Regulated DC Power Supply Circuit

1.2V – 57V Regulated DC Power Supply Circuit
This is the circuit diagram of multi purpose regulated dc power supply which featured with short circuit protection. The electronic workshop is necessary to have a source capable of providing any voltage and sufficient current within an acceptable range of possibilities. This circuit goes beyond conventional sources (which rarely exceed 24V output) giving a maximum of 57V with a current of 1.5A. (more…)