12V DC Power Supply without Transformer

On December 9th, 2014 by psu | No Comments | Posted in Power Supply Circuit, Unregulated Power Supply

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 output device.

12V PSU without transformer
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1.2V – 57V Regulated DC Power Supply Circuit

On November 18th, 2014 by psu | No Comments | Posted in Regulated Power Supply, Variable Power Supply

1.2V - 57V Regulated 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.
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Power Supply Calculator for Server and Desktop Computer

On October 4th, 2014 by psu | No Comments | Posted in ATX Power Supply

PC power supply

These are the recommended websites which provide online power supply calculator for server and desktop computer. This tool used to calculate the estimate wattage of power supply which should be used for computers depends the computer specification.
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1.5A Negative Adjustable Power Supply

On September 15th, 2014 by psu | No Comments | Posted in Regulated Power Supply

Negative Adjustable Power Supply Schematic Diagram

This is the circuit diagram of negative adjustable power supply based LM337T. This circuit can be used for devices which required negative supply to work. The regulator LM337T is capable of supplying 1.5A over an input voltage range of 1.2V to 37V. They need at least a 2.5V input-output voltage differential. In practice the limiting factor on the output voltage & current will be the power dissipated by the regulator. For example, if the input voltage is 30V & the output voltage is 10V and the output current is 1A then the power dissipated by the heatsink is (30-10)*1 or 20W. This would need a big heatsink. So it is desirable to keep the input voltage as low as possible to achieve the required output.
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12V / 10A Switching Power Supply

On July 31st, 2014 by psu | No Comments | Posted in Switching Power Supply

12V 10A Switching Power Supply Circuit Diagram

This is the circuit diagram of 12V / 10A switching power supply. The circuit, shown in the schematic, provides 12 volts, at 10 amperes, maximum, using a discrete transistor regulator with an op-amp functioning as a comparator in the feedback circuit. The supply was constructed in 1984 and is variable frequency, as opposed to the pulse width modulator (PWM) controllers used today. The transformer used in this design diagram was for 110-120VAC home electric main, you should change the transformer which has 220V primary if your home electric installation use 220VAC.
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