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

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

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