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

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

Adjustable Regulated Power Supply 0-15V / 1A

Adjustable Regulated Power Supply 0-15V / 1A
This is the schematic diagram of adjustable power supply which the voltage output can be vary from 0V up to 15V with fixed current output maximum of 1A. The circuit is very simple and easy to build, finding the components is easy and inexpensive. The output voltage is stabilized and regulated in the range of 0V to +15 V, supplied with a maximum current of 1 A. (more…)

40V Regulated Power Supply based TIP42A and LM317

40V Regulated Power Supply based TIP42A and LM317
This is a 40V Regulated Power Supply, built using IC LM317 as regulator and TIP42A as electric current amplifier. Component part:  Regulated Power Supply R1 = 3R9 1 or 2W R2 = 22R R3 = 6K8 R4 = 220R R5 = 4K7 C1 = 3300µF/50V or 4700µF/50V C2,C5 = 100nF C3 = 10µF/63V C4 = 220µF/50V D1 = Diode bridge 100V 4A D2 = 1N4002 D3 = LED IC1 = LM317T Q1 = TIP42A SW2 = SPST Mains switch