The LM317HV is an adjustable 3-terminal positive voltage regulator capable of supplying 1.5 A or more currents over a 1.25V to 57V output voltage range. It requires only two external resistors to set the output voltage. The LM317HV is packaged in standard transistor packages that are easily mounted and handled.
However, the LM317HV supports high voltage, but the current is still low, only 1.5A, our circuit, we are increasing a drive circuit to increase the current we need to 6 Amps, with three TIP36C transistors, which provides an adjustable output voltage between 1.25v to 57 volts, with a current of 6 Amps, which is enough for a bench power supply.
The schematic electrical diagram, which follows in Figure 2 below, it's very simple, first one, we have the voltage input that comes through connector J1, which enters through resistor R1, that as long as there is no current greater than the one calculated, there is no drop of voltage in R1, more if the current increases, there will be a voltage drop of approximately 0.6V, which will cause the transistors to saturate, causing the current to pass through the power transistors.
The capacitor C1 has the objective of attenuating the interference of the ripples and their stability. Capacitor C2 has the function of eliminating high interference, and capacitor C3 has the function of constancy to decrease the ripple and stability of the power supply.
P1, is a 5K analog potentiometer, if you don’t have 5K you can put 4.7K, which is more commercial, the diodes D1 and D2 are to avoid reverse voltage over the Integrated Circuit U1, and in the transistors, resistors R3, R4 and R5, are impact resistors, which attenuate the difference between the transistors and prevent one from working more than the other.
Fig. 2- Adjustable Power Supply Schematic LM317HV + TIP36
Components list
U1…………….... LM317HV – Integrated circuit, voltage regulator
Others ............… Printed Circuit Board, tin, wire, etc.
We are offering to Download the link with the printed circuit board printing files, they are; Gerber, PDF layout, PNG, all the files with a direct link to Mega.
Hi @Myron 1. Yes you can, just remembering that the TIP36C is 100V, 25A, 125W and the 2SB817 is 160V, 12A, 100W. 2. In this circuit, there is no overcurrent or short circuit protection. My regards!
Thank you so much for sharing this design. I have 2 questions:
ReplyDelete1. Can you advise if I can replace the TIP36C transistors with 2SB817 to the design above?
2, Is there a design of the above to limit max current as well?
Kind regards! Myron
Hi @Myron
Delete1. Yes you can, just remembering that the TIP36C is 100V, 25A, 125W and the 2SB817 is 160V, 12A, 100W.
2. In this circuit, there is no overcurrent or short circuit protection.
My regards!