schematic knowledge

Showing posts with label volt. Show all posts

Sunday, May 5, 2013

Simple Dual Voltage Power Supply 12 Volt

This is the simple circuit diagram of Dual Voltage Power Supply. It is used for Misc… application. This circuit is called regulated power supply. For this reason the main component of this circuit is Regulator IC. It also needs few components to built. The regulator 7812 is the positive voltage regulator and 7912 is the negative voltage regulator.

You can also use 7809 for 9 volt positive power supply and 7909 for negative voltage power supply. It regulates voltage from 24Volt to 12 Volt (DC). The transformer input is 110Volt to 220Volt (AC) and the output must be between 12Volt to 24Volt (AC) and current must be 500mA. In this circuit some capacitors are used as a filter for removing repole.

Saturday, April 13, 2013

12 Volt Battery Guardian

Dont get caught with a flat battery; this easy-to-build circuit can cut off the energy to a 12V fridge or automotive stereo device if the battery voltages drops beneath critical level. Electric fridges in trucks and 4 wheel drives are a actually perfect idea but if you're not automobileeful, they are able to severely discharge the battery and go away you stranded. Maybe the battery will end up with extreme injury as well. The same downside applies when you have an important stereo gadget and you like to play it without the motor running.

Main characteristics:

Cuts power to load (eg, fridge) when battery voltage drops under a preset stage.
10A rating.
Low energy drain.
Chirping sound throughout cut-out.
Flashing LED indication all through cut-out.
Automatically reconnects energy when battery recharged.

Operation on 12V is fine when the motor is working and battery cost is maintained but if the fridge is allowed to run for too lengthy when the motor is stopped, it could neatly flatten the battery in a slightly short time. This is where the Battery Guardian comes into play. It displays the battery voltage and disconnects energy to the fridge sooner than the battery develop intos too flat to allow the engine to be began again.

Parts layout:

PCB layout:

Circuit diagram:

Source: Silicon Chip 6 May 2002

Wednesday, April 10, 2013

5 Volt Switching Regulator Power Supply

The switching regulator power supply used LM2575-5.0 on this schematic. You can make the stable voltage by using the 3 terminal regulator like LM317. However, because the output electric current and the inputted electric current are the same approximately, the difference between the input electric power (The input voltage x The input electric current) and the output power (The output voltage x The output current) is consumed as the heat with the regulator. Because it is, the efficiency isn�t good.

Data sheet for LM2575

SIMPLE SWITCHER 1A Step-Down Voltage Regulator

http://www.national.com/pf/LM/LM2575.htm

Tuesday, April 9, 2013

6 to 12 Volt Converter

Below its a converter circuit voltage from 6 Volt to 12 Volt DC.

6 Volt to 12 Volt DC

Part List :
R1, R4 2 .2K 1/4W Resistor
R2, R3 4.7K 1/4W Resistor
R5 1K 1/4W Resistor
R6 1.5K 1/4W Resistor
R7 33K 1/4W Resistor
R8 10K 1/4W Resistor
C1,C2 0.1uF Ceramic Disc Capacitor
C3 470uF 25V Electrolytic Capcitor
D1 1N914 Diode
D2 1N4004 Diode
D3 12V 400mW Zener Diode
Q1, Q2, Q4 BC547 NPN Transistor
Q3 BD679 NPN Transistor
L1 See Notes
Notes
1. L1 is a custom inductor wound with about 80 turns of 0.5mm magnet wire around a toroidal core with a 40mm outside diameter.

2. Different values of D3 can be used to get different output voltages from about 0.6V to around 30V. Note that at higher voltages the circuit might not perform as well and may not produce as much current. You may also need to use a larger C3 for higher voltages and/or higher currents.

3. You can use a larger value for C3 to provide better filtering.

4. The circuit will require about 2A from the 6V supply to provide the full 800mA at 12V.

Friday, March 29, 2013

12 Volt DC Fluorescent Lamp Driver

A number of people have been unable to find the transformer needed for the Black Light project, so I looked around to see if I could find a fluorescent lamp driver that does not require any special components. I finally found one in Electronics Now. Here it is. It uses a normal 120 to 6V stepdown transformer in reverse to step 12V to about 350V to drive a lamp without the need to warm the filaments.

12 Volt DC Fluorescent Lamp Driver circuit diagram

Parts:

C1 100uf 25V Electrolytic Capacitor
C2,C3 0.01uf 25V Ceramic Disc Capacitor
C4 0.01uf 1KV Ceramic Disc Capacitor
R1 1K 1/4W Resistor
R2 2.7K 1/4W Resistor
Q1 IRF510 MOSFET
U1 TLC555 Timer IC
T1 6V 300mA Transformer
LAMP 4W Fluorescent Lamp
MISC Board, Wire, Heatsink For Q1

Notes:

Q1 must be installed on a heat sink.
A 240V to 10V transformer will work better then the one in the parts list. The problem is that they are hard to find.
This circuit can give a nasty (but not too dangerous) shock. Be careful around the output leads.

Thursday, March 21, 2013

1 5 35 Volt DC Regulated Power Supply

Here is the circuit diagram of regulated power supply. It is a small power supply that provides a regulated voltage, adjustable between 1.5 and 35 volts at 1 ampere. This circuit is ready to use, you just need to add a suitable transformer. This circuit is thermal overload protected because the current limiter and thermal overload protection are included in the IC.

Picture of the circuit:

1A 1.5 volt to 35 volt dc Regulated Power Supply Circuit Schematic

1A Regulated Power Supply Circuit Schematic

Circuit diagram:

1A Regulated Power Supply Circuit Diagram

Transformer selection chart:

Transformer selection Guide-Table For Power Supply

Parts:

IC = LM317
P1 = 4.7K
R1 = 120R
C1 = 100nF - 63V
C2 = 1uF - 35V
C3 = 10uF - 35V
C4 = 2200uF - 35V
D1-D4 = 1N4007

Features:

Just add a suitable transformer (see table)
Great to power your projects and save money on batteries
Suitable as an adjustable power supply for experiments
Control DC motors, low voltage light bulbs, …

Specifications :

Preset any voltage between 1.5 and 35V
Very low ripple (80dB rejection)
Short-circuit, thermal and overload protection
Max input voltage : 28VAC or 40VDC
Max dissipation : 15W (with heatsink)
Dimensions : 52x52mm (2.1” x 2.1”)

Technical Specifications

Input Voltage = 40Vdc max Transformer
Output Voltage = 1.5V to 35Vdc
Output Current = 1.5 Amps max.
Power Dissipation = 15W max (cooled)

Note:

It has not to be cooled if used for small powers. 28 Volt AC max is allowed for the input voltage.