Adjustable Power Supply Schematic | Electronic Project Circuits

Posts Tagged ‘adjustable power supply schematic’

40V Regulated Power Supply by LM317+TIP42

A very good and powerful Regulated Power Supply section was implemented by simply adding a PNP power transistor to the excellent LM317T adjustable regulator chip. In this way this circuit was able to deliver much more than the power required to drive two Mini-MosFet amplifiers to full output (at least 2Amp @ 40V into 4 Ohm load) without any appreciable effort.

Regulated Power Supply Parts:
R1_______________3R9 1 or 2W Resistor
R2______________22R 1/4W Resistor
R3_______________6K8 1/4W Resistor
R4_____________220R 1/4W Resistor
R5_______________4K7 1/2W Resistor
C1____________3300µF 50V Electrolytic Capacitor (or 4700µF 50V)
C2,C5__________100nF 63V Polyester Capacitors
C3______________10µF 63V Electrolytic Capacitor
C4_____________220µF 50V Electrolytic Capacitor
D1_____Diode bridge 100V 4A
D2___________1N4002 200V 1A Diode
D3______________LED Any type and color
IC1___________LM317T 3-Terminal Adjustable Regulator
Q1____________TIP42A 60V 6A PNP Transistor
SW2_____________SPST Mains switch
T1_____________230V Primary, 35-36V (Center-tapped) Secondary,
50-75VA Mains transformer (See Notes)
PL1____________Male Mains plug with cord

Please read more at the original source: http://www.redcircuits.com/Page123.htm

Be the first to comment - What do you think? Posted by admin - September 24, 2007 at 1:23 pm

Categories: Power supply Tags: adjustable power supply schematic, variable regulated power supply

Power Supply 0-300V DC Adjustable

This is circuit high voltage Power Supply DC Adjustable Voltage 0-300V 100mA max. It is a simple circuit which can provide an adjustable voltage source of 0 to 330 Volt..
The supply is short-ciruit proof: the current is limited to about 100mA.

0-300V power supply schematic:

To prevent my high voltage experiments to go up in smoke completely, I designed
a simple circuit which can provide an adjustable voltage source of 0 to 330 Volt..
The supply is short-ciruit proof: the current is limited to about 100mA.

Circuit description
TR1 is a 1:1 mains transformer; it is included for safety.
The mains voltage from TR1 is rectified with bridge D1 (1Amp / 500V) and large elcap C1.
T1 is switched as a source follower: the source of T1 will follow the voltage of the
wiper of R3. D2 is included to protect the gate of T1; although in theory not necessary
I strongly recommend to include it!

T2 and shunt resistor R2 build the current limiter. When the output current becomes too high, T2 will discharge
the gate of T1. This will prevent the current to become too high.
The value of R3 has been determined experimentally; it depends also on the Hfe of T2 so you may need to tune the value of R2.

Note that T1 needs a large heatsink: in worst case T1 will dissipate 330V x 100mA = 33Watt!
Instead of a BUZ 326 (400V/10.5Amp) you can also use an IRF740 (400V/10Amp).
The output impedance of the power supply is determined by the beta of T1, so the larger the MOSFET
the lower the output impedance!

Thank you Source :

http://www.geocities.com/tjacodesign/300vsup/300vsup.html

Be the first to comment - What do you think? Posted by admin - July 31, 2007 at 10:36 pm

Categories: Power supply, Variable Regulator Tags: adjustable power supply schematic, High voltage, Variable-DC-Power-Supply

LM350 Regulator 3-Amp Adjustable

With the component values shown the circuit is designed to have and output voltage range of approximately 1.25 to 13.5 Volts when measured at the output of the regulator. The calculation on the drawing is used to determine the output voltage for given values of R1 and R2.

Because these regulators have a minimum output voltage of 1.25 Volts diodes D3 and D4 will provide a voltage drop of approximately 1.4 Volts so that zero output to the track can be obtained. These diodes need to have at least a 3 amp rating

The diodes D1 and D2 added to the circuit will prevent damage to the regulator during certain adverse conditions such as the output voltage being higher than the input voltage to the regulator. This can happen if this type of circuit is used as a variable power supply for an electronics test bench and without the added protection of D3 and D4.

A substantial heat sink will be needed for the TTR as quite a bit of heat will be generated when drawing high current with low output voltages. For this reason this circuit is not recommended for use in hand held throttles.

If the less expensive LM 317 regulator is used this circuit makes an excellent test bench power supply just leave out D3 and 4 and add a voltmeter.

Source :: http://home.cogeco.ca/~rpaisley4/TTRThrottle.html