LT1086 Negative Voltage Regulator

This is the efficient negative voltage regulator circuit built based IC LT1086.

One way to provide good negative-voltage regulation is with a low-dropout positive-voltage regulator operating from a well-isolated secondary winding of switch-mode circuit transformer. The technique works with any positive-voltage regulator, although highest efficiency occurs with low-dropout types.

Under all loading conditions, the minimum voltage difference between the regulator VIN and V0UT pins must be at least 1.5V, the LT1086's low-dropout voltage. If this requirement isn't met, the output falls out of regulation. Two programming resistors, R1 and R2, set the output voltage to 12 V, and the LT1086's servo the voltage between the output and its adjusting (ADJ) terminals to 1.25 V. Capacitor C1 improves ripple rejection, and protection diode D1 eliminates common-load problems.

Since a secondary winding is galvanically isolated, a regulator's 12 V output can be referenced to ground. Therefore, in the case of a negative-voltage output, the positive-voltage terminal of the regulator connects to ground, and the -12 V output comes off the anode of D1. The VIN terminal floats at 1.5 V or more above ground.

LT1086 Negative voltage regulator circuit diagram.

Comments

LM317T Voltage Regulator Circuit with Pass Transistor

This is the schematic diagram of voltage regulator circuit with pass transostor. The regulator is based regulator IC of LM317T. The LM317T output current can be raised by utilizing an additional power transistor (on circuit, it is 2N2955) to share a portion of the total current. The amount of current sharing is established with a resistor placed in series with the LM317 input and a resistor placed in series with the emitter of the pass transistor. In the above scheme design , the pass transistor will start conducting when the LM317 current reaches about 1 ampere, due to the voltage drop across the 0.7 ohm resistor. Current limiting happens at about 2 amperes for the LM317 which will drop about 1.4 volts across the 0.7 ohm resistor and make a 700 millivolt drop across the 0.3 ohm emitter resistor. Thus the total current is limited to about 2+ (.7/.3) = 4.3 amperes.

6V to 12V DC Voltage Doubler

Here is the 6V to 12V DC voltage doubler circuit design, it also called DC voltage miltiplier or DC to DC converter. This dc voltage doubler circuit will need about 2A from the 6V input supply to produce the full 800mA at 12V for the power output. This circuit is very useful to generate higher voltage from a low power source, but this circuit will deliver low output current. So it should only be used for low current driven applications. Also, the output voltage may be unstable, so a voltage regulator (IC78XX) of proper rating can be used regulation and smooth output. But voltage regulator IC itself consume some current, and reduce the deliverable current.

Solid State Tesla Coil with 555 Timer

Here the circuit diagram of solid state tesla coil with 555 timer. Single transistor flyback driver induced a lot of complications on account of it really is operating principle. I received e-mails from those who had been unable to obtain it functional even after they are positive that their flyback and transistor is Okay. Moreover, because it is resonance frequency is determined by each individual a part of the method, any time you seek to draw an arc in the transformer, it alterations substantially in a lot of the circumstances. Simply because the operating frequency is vital for your security criteria, (each for mine and electrical power transistor's), I determined to generate it run on a continuous frequency and developed up yet another easy circuit, attempting to keep within the specified limits in the 555 timer.

Power Supply Adapter

Search This Blog