1 3V DC to 12 2V DC Regulator Power Supply

Power supply circuit to generate output below were variations between 1.3V DC to 12.2V DC with 1A current.
In addition, the power supply circuit is also equipped with over-current protection or shield against belebih flow. Power supply circuit is very simple, but the quality is quite good, made her basiskan regulator IC LM723 is a pretty legendary.

Description:

R2 to set the output voltage. The maximum current is determined by R3, over-current protection circuit inside the LM723 to detect the voltage on R3, if it reaches 0.65 V, the voltage output will be off her. So the current through R3 can not exceed 0.65 / R3 although output short-circuit in his.

C3 and C4 are ceramic capacitors, as much as possible directly soldered to the PCB, this is because the LM723 is prone to oscillation that is not cool.

LM723 works with 9.5V input voltage to 40 V DC and the LM723 can generate its own current of 150mA when the output voltage is not more than 6-7V under input voltage.



Specifications:

Output (value estimated):

Vmin = (R4 + R5) / (R5 * 1.3)
Vmax = (7.15 / R5) * (R4 + R5)
Imax = 0.65/R3
Max. Power on R3: 0.42/R3


Min. DC Input Voltage (pin 12 to pin 7): Vmax + 5

Component List:

B1 40V/2.5A
C1 2200uF (3300uF even better)
C2 4.7uF
C3 100nF
C4 1NF
C5 330nF
C6 100uF
Green LED D1
D2 1N4003
F1 0.2A F
F2 2A M
IC1 LM723 (in a DIL14 plastic package)
R1 1k
R2 Pot. 5k
R3 0.56R/2W
R4 3.3k
R5 4.7k
S1 250V/1A
T1 2N3055 on a heatsink 5K / W
TR1 220V/17V/1.5

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MSK5012 Adjustable Voltage Regulator 10A

 MSK5012 is a awful reliable adjustable voltage regulator.Whose achievement can be programmed application two resistors. The regulator has a actual low dropout voltage(0.45v @10A )due to the acceptance of MOSFT with actual low Rds (ON) as the centralized alternation canyon element.The MS5012 has a top akin of accurateness and ripple bounce is about 45dB. It is accessible in a 5 pin Sip amalgamation that is electrically abandoned from the centralized circuitry. This accord us the abandon to fit the IC anon to the calefaction bore and this array of absolute heatsinking improves the thermal dissipation. 

The achievement voltage of this circuit is adjustable from 1.3v to 36v DC.Resistors R1 and R2 are acclimated for programming the achievement voltage. For all applications, amount of R2 is anchored to 10K. The accord amid R1,R2 and achievement voltage Vout is according to the blueprint R1=R2(Vout/1.235)-1. C1 is a clarify capacitor which is aswell a allotment of the aboideau drive circuit of the centralized alternation canyon MOSFET. About three times the ascribe voltage will arise beyond this capacitor and so the its voltage appraisement have to be called accordingly.C2 is the ascribe clarify capacitor while C3 is the achievement clarify capacitor.

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Low drop Regulator with Indicator

Even today much logic is still powered from 5 volts and it then seems obvious to power the circuit using a standard regulator from a rectangular 9-V battery. A disadvantage of this approach is that the capacity of a 9-V battery is rather low and the price is rather high. Even the NiMH revolution, which has resulted in considerably higher capacities of (pen-light) batteries, seems to have escaped the 9-V battery generation. It would be cheaper if 5 volts could be derived from 6 volts, for example. That would be 4 ‘normal’ cells or 5 NiMH- cells. Also the ‘old fashioned’ sealed lead- acid battery would be appropriate, or two lithium cells.

 

Circuit diagram : 

Low-drop Regulator with Indicator Circuit Diagram

 

Using an LP2951, such a power supply is easily realised. The LP2951 is an ever- green from National Semiconductor, which you will have encountered in numerous  Elektor Electronics designs already. This IC can deliver a maximum current of 100 mA at an input voltage of greater than 5.4 V. In addition to this particular version, there are also versions available for 3.3 and 3 V output, as well as an adjustable version.  In this design we have added a battery indicator, which also protects the battery from too deep a discharge. As soon as the IC has a problem with too low an input voltage, the ERROR output will go low and the regulator is turned off via IC2d, until a manual restart is provided with the RESET pushbutton.

 

The battery voltage is divided with a few resistors and compared with the reference voltage (1.23 V) of the regulator IC. To adapt the indicator for different voltages you only need to change the 100-k resistor. The comparator is an LP339. This is an energy-friendly version of the LM339. The LP339 consumes only 60 µA and can sink 30 mA at its output. You can also use the LM339, if you happen to have one around, but the current consumption in that case is 14 times higher (which, for that matter, is still less than 1 mA).

 

Finally, the LP2951 in the idle state, consumes about 100 µA and depend- ing on the output current to be deliv- ered, a little more. 

Author : Karel Walraven - Copyright : Elektor

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