Panel switch wiring

Showing posts with label dc. Show all posts

Tuesday, January 6, 2015

Step Down DC Converter

This is a ADP1821 Step Down DC-to-DC Converter circuit.

This circuit uses ADP1821 that is synchronous pulse-width-modulated (PWM), step-down controller, inexpensive and versatile.

It can drive all N-channel power stage to regulate an output voltage as low as 0.6 V.

Sunday, October 19, 2014

LM2577 12V to 16V DC DC Converter

The circuit is a boost step-up regulator based around an LM2577-ADJ voltage regulator chip and a few other discrete components. Resistors R1 and R2 set the regulated output voltage.

A switch inside the voltage regulator closes between pins 4 and 3, causing current to flow through the inductor to ground. When the switch is released a few microseconds later, a back-EMF ‘kick’ is produced by the inductor, resulting in a positive pulse with respect to the input voltage. This pulse charges the output capacitor via the schottky diode, which tends towards an equilibrium voltage.
The switch continues to oscillate, the diode preventing the switch from shorting the output capacitor during the ‘on’ phase. The output voltage is monitored via the voltage divider R1/R2, causing the duty cycle of the switch oscillator to be continuously regulated in order to maintain a constant output voltage under varying loads.
Source: http://www.mcrent.com/workbench/dcdc1216/

Wednesday, September 10, 2014

9 Volt DC Power Supply Using LM317 Regulator

There are many ways to obtain a very stable voltage 9VDC which has very minimal distortion. If you really love in the audio field, you must have a power supply at the level of the OP Amp should be free from hum. Use of Power Supply which has a higher stabilization and free of humming and buzzing frequently encountered in the use of communication tools such as Handy-talkie and radio transmitters.

To overcome the above problem, we have to provide the filters on the power supply using IC regulator. You can use the LM 7809 or you can also use the regulator IC LM 317. This regulator has advantages over the use of IC 78XX. LM317 has a nature that is at the Gate (no.1 feet) can be tuned to provide feedback which is inversely proportional to the value of R (resistor). The R value can affect the output voltage on pin 2(V-out), pin 3 as input (V-in). The function R can be replaced with a variable resistor, but you must have an indicator meter or AVO meter to ensure that the output voltage is true 9 Volt. If youve found your desired voltage, for example 9VDC, then you can connect to the component that you want to turn on. So first set the output voltage using a volt meter before connecting to the equipment to be you turn on.

KA317 / LM317 is a Three Terminal Positive Adjustable Regulator integrated schema, the monolithic characteristic adjustable positive voltage regulator designed to supply more than 1.5 A of load current with output voltage can be adjusted with a range capability 1.2 V of up to 37 V. This tool will work for internal current limiting, thermal shut-down and securing the compensation scope. You have to use aluminum as an additional cooling.

This schema will deliver 9V regulated DC voltage at maximum current of about 1A. The schema uses a transformer with a secondary output voltage 15-24V AC/1A. To give input in Primary of transformer, it’s dependent electrical conduit installation in your home. If the mains voltage 110V, then you have to find a 110V in transformer primary voltage. For the diode, you can use 4 pieces diodes 1N4002 (1A rectifier diode) or better by using a diode bridge 2A.

9 Volt DC Power Supply Using LM317 Regulator

In the following schema scheme, we can see the typical basic application into obtaining voltage can be adjusted.

Tuesday, September 9, 2014

Precision Full Wave Ac Dc Converter Wiring diagram Schematic

A dc level is produced that corresponds to the ac input rms value (if sine wave), -i set the gain of IC2 to 1.11. This factor is the average-to-rms conversion factor. IC1 and IC2 act as a full-wave rectifier schema, with Dl and D2.

Precision Full-Wave Ac/Dc Converter Circuit Diagram

Thursday, September 4, 2014

Build a 250 to 5000 watts PWM DC AC 220V Power Inverter

Build a 250 to 5000 watts PWM DC/AC 220V Power Inverter

This is my schematic design of a Pulse Width Modulator DC/AC inverter using the chip SG3524 .
I have built this design and using it as a backup to power up all my house when outages occur.

If you like my work and intend to build the schema dont forget to give me the 5 satrs :D and subscribe to me by clicking on the "follow" button so I know how many people benefit from the design, Thanks

Notes:

>The schematic schema design is for a 250 watt output, while the pics are of my 1500 watts inverter that i built, to increase the power of the schema you have to add more of the Q7 and Q8 transistors in parallel, each pair you add will increase your power by 250 watts, ex: to get 750 watts of power from the inverter you need to add in parallel 2 of Q7 and 2 of Q8 to the original design.

>If you increase the power transistors you have to enlarge the T2 transformer to match the new needs, the diagram transformer is rated 25 amps to handle 250 watts of 220v, for every 1 additional amp you need on the 220v side you have to increase 10 amps on the 12v side, of course there are limits to the thickness of the winding so if you need more than 750 watts i recommend that you use a 24VDC supply instead of 12 volts:

DC voltage and Transformer "T2" winding recommendation:
Power     Supply     Winding
750w       12VDC     P:24V "12-0-12" / S:220V
1500w     24VDC     P:48V "24-0-24" / S:220V
2250w     36VDC     P:72V "36-0-36" / S:220V
3000w     48VDC     P:96V "48-0-48" / S:220V
3750w     60VDC     P:120V "60-0-60" / S:220V
4500w     72VDC     P:144V "72-0-72" / S:220V
5250w     84VDC     P:168V "84-0-84" / S:220V
*The transformer should be "center tapped" at the primary side.
**You can make the secondary 110v if needed.
***The transformer in the pic is a custom made (48V center tapped / 220v ) 2000 watts, weights like 10 kilos.

>R1 is to set the PWM duty cycle to 220v. Connect voltmeter to the output of your inverter and vary VR1 till the voltage reads 220V.

>R2 is to set the frequency to 50 or 60 Hz (R2 range is between 40Hz to 75Hz), so guys that do not have a frequency meter are advised to blindly put this variable resistor mid-way which should drop you in the range of 50~60 Hz.
If you want you can substitue the variable resistor with a fixed resistor using the following formula: F = 1.3 / (RxC)
in our case to get a 50Hz output we remove both the 100K and the variable 100K both from pin 6 and we put instead a 260K fixed resistor and we leave the 0.1uF (the 104 cap) as it is, this change should give out a fixed 50Hz as per the formula :
1.3 / (260,000 ohm x 0.0000001 farad) = 50Hz
But in reality it will not exactly give 50Hz because the 260K resistor has a specific error value margin so does the capacitor, thats why i recommend a variable resistor so that accurate calibration can be achieved.

>Use either tantalum or polyester film "as in pic" for the 104 caps, ceramic disc caps change value once hot and this in turn changes the frequency of the inverter so they are not recommended.

>Pin 10 of the SG3524 can be used to auto shut down the inverter, once a positive voltage is given instead of negative to pin10, the SG3524 will stop oscillating. This is useful for persons wanting to add some cosmetic makeup to their inverters like overload cutoff, low battery cutoff or overheating cutoff.

>Wiring connections on the power stage side should be thick enough to handle the huge amps drain from the batteries. I marked them with dark black on the schema also I included a pic so you see how thick those wires must be.

>The design does not include a battery charger since each person will be building a custom version of the inverter with specific power needs. If you are ordering a custom made transformer you can ask them to take out for you an additional output wire on the primary side to give 14v (between point 0 and this new wire) and use it to charge a 12v battery, of course this needs a seperate schema to control charging auto cut-off. But anyway this is not advisable because it will shorten the life of the transformer itself since using it as a charger will toast the enamel coating layer of the copper wires over time. Anyway .. YES can be done to reduce cost.

>A cooling fan will be needed to reduce heat off the heat sinks and transformer, i recommend getting a 220v fan and connecting it to the output T2 transformer, when you power up the schema the fan will start this will always give you a simple way to know that 220v is present and everything is OK.. You can use a computers old power supply fan if you like.
Note that the fan must suck air out from the inverter case and NOT blow inside, so install it the correct way or it will be useless.
Also note how I fixed both the heat sinks and where the fan is, in a way that the fan sucks hot air from like a channel between the 2 heatsinks.

>2 schema breakers are recommended instead of fuses, one on the DC side and one on the AC side, depending on your design
Ex: for a 24vDC ( 1500 watts design ) put a 60Amp breaker on the DC side and a 6Amp on the AC side.
For every 1amp of 220vAC you will be draining like 8 to 10 Amps from the 12v battery, make your calculations !

> The 2 Heat sinks should be big enough to cool the transistors, they are separate and should NOT touch each other. "see the pics"

>Important: If youre building a big design that uses more than 24VDC as power source, make sure not to supply the driver schema with more than 24v maximum. (EX: If you have 4 batteries 4x12 = 48v , connect the v+ supply of the driver schema to the second batterys (+) terminal with a thin 1 mm wire which is more than enough. this supplies the driver schema with +24v while supplies the power transformer with +48v)

> "Optional" : Deep Cycle batteries are your best choice, consider them for best results .. read more

> Be cautious when building this schema it involves high voltage which is lethal, any part you touch when the schema is ON could give you a nasty painful jolt, specially the heat-sinks, never touch them when the schema is on to see if the transistors are hot !! I ate it several times :)

> The optional "Low voltage warning" is already embedded in the PCB layout, you can disregard it and not install its components if you do not needed. It does not affect the functionality of the main schema.

> The Motorola 2N6277 is a heavy duty power transistor, it is used in many US tanks for its reliability but unfortunately it is a very hard to find part, instead you can substitute each 2N6277 with 2 x 2N3773 or any equivalent.

> Ive included an optional "Battery level indicator" schema diagram that has 4 LEDs, you can see it installed on the front panel of my inverter pic, it is functioning great and shows precisely how much juice the batteries still have. I have included a small relay that is powered by the last LED to auto shutoff the inverter once last LED is off.

>Also included an optional "Overload schema", it is very easy to build and can be calibrated to the desired overload current threshold cutoff point through the potentiometer VR1.

R1 is rated 5watts for inverters upto 1000 watts. For bigger versions of the inverter like 1000 to 3000 watts inverters, replace R1 (1 ohm, 5watts) with (1 ohm, 17watts) which should handle loads upto 10 VA.
Make sure you install a proper relay to handle big current drains.

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Friday, August 29, 2014

DC Motor Speed Controller

DC Motor Speed Controller Circuit Diagram. This schema takes advantage of the voltage drop across bridge rectifier diodes to produce a 5-position variable voltage supply to a DC fan or other small DC motor. It is not as efficient as a switch-mode schema but it has the virtues of simplicity and no switching hash. The four full-wave bridges are connected so that each has two pairs of series diodes in parallel, giving a voltage drop of about 1.4V, depending on the load current.

DC Motor Speed Controller Circuit Diagram

The rotary switch should have "make before break" contacts which should be rated to take currents up to about an amp or so. For higher currents, higher rated bridge rectifiers and a suitably rugged rotary switch (or solenoids) will be required. If you want smaller voltage steps, you could use the commoned AC inputs on the bridge rectifiers to give intermediate steps on the speed switch.

Author: Stephen Butcher,

Thursday, August 28, 2014

Inverter 12 V DC to 120 V AC

This Inverter takes 12 volt d.c and steps it up to 120 volt a.c. The wattage depends on which transistors you use for Q1 and Q2, as well as the "Amp Rating" of the transformer you use for T1. This inverter can be constructed to supply anywhere from 1 to 1000 (1 KW) watts. If Q1, Q2 are 2N3055 NPN Transistors and T1 is a 15 A transformer, then the inverter will supply about 300 watts. Larger transformers and more powerful transistors can be substituted for T1, Q1 and Q2 for more power.

Parts
C1, C2 >> 68 uf, 25 V Tantalum Capacitor
R1, R2 >> 10 Ohm, 5 Watt Resistor
R3, R4 >> 180 Ohm, 1 Watt Resistor
D1, D2 >> HEP 154 Silicon Diode
Q1, Q2 >> 2N3055 NPN Transistor (see "Notes")
T1 >> 24V, Center Tapped Transformer
Misc:
Wire, Case, Receptacle (for output)
Fuses, Heatsinks, etc.

Note: Dont try to run inductive loads (motors...) off this inverter.

Wednesday, August 27, 2014

Speed Control of DC Motor PWM Wiring diagram Schematic

Speed Control of DC Motor PWM Circuit Diagram. Often, people try to control small DC motors with a variable resistor type potentiometer connected to a transistor. This system until works well but it generates heat and thus loses power. This schema is a simple schema for modulating the pulse width for controlling the DC motor, it eliminates this problem.

Speed Control of DC Motor PWM Circuit Diagram

The schema is capable of controlling the engine speed pulses (PWM), these pulses have a duration variable to change the speed of the motor. The longer the pulses lead, the faster the motor will rotate, and vice versa.

R1 1 Meg 1/4W Resistor
R2 Potentiometer 100K
C1 0.1uF 25V Capacitor Ceramic Disc
C2 0.01uF 25V Capacitor Ceramic Disc
Q1 MOSFET IRF511 or IRF620
U1 4011 CMOS NAND
S1 KEY
M1 Motor

The resistor R2 adjusts the speed of the oscillator and thus the speed of the motor, the motor can be any DC motor that operates from 6V and having no more power than the maximum current of Q1. The voltage can be increased by connection to a higher voltage to switch instead of 6V which feeds the oscillator.The Q1 will need a heat-sink. If you need to use the IRF620 that supports up to 6A.

Sunday, August 24, 2014

Rectifier to convert AC to DC

What is rectifier:-
A device which converts Alternating Current to Direct Current, its schema is based on four diodes connected in such a way that they convert AC (alternating current ) to DC (Direct current).

How it works:-
First let me explain for newbies who dontt now about AC or DC, AC is an alternating current which changes its phase on every cycle, there are two cycles during first cycle amplitude of voltage is postive but during second cycle its amplitude is negative, number of cycle in a second is called frequency.
Usually frequency is about 50Hz but in some countries it is 60Hz, Ill explain you later on why frequency is 50Hz or 60Hz.

Now coming to DC a direct current, no change in phase, that is its frequency is 0Hz, its amplitude remain same through out its conductance
As i said its schema is based on diodes, let me first explain you what is diode?
diode is semiconductor device thats is use to allow current to flow in one direction, in simple words its act as a volue which allow current in one direction, it may be forward bised or in reverse biase, it allows current to flow in forward biased mode, and stops during reverse biased.Now there is another question what is forward biased or reverse biase, forward biase is a mode in which anode of diode is a high potential and cathode is a low potential, while in reverse biased cathode is a high potential and anode is a low potential they are opposite of each other.

Now coming back to my topic, rectified is based on four diodes, when we supply AC, diode allow current during positive cycle but during negative cycle diodes are connected in reversed condition connected in such a way that it allows negative cycle of current too, in this way whole cycle pass away through diodes, now it in DC form, but not pure DC there are some hormonics component of AC too, but dont worry they can be eliminated by using polar capacitor which removes ripples or hormonics coming out, in this way we get pure DC, to make it regulated power supply we can attack a regulator ic LM317 or 7809 and other regulator.

Uses:-
Mostly commonly it is used in as power supply for various appliances like Laptop charger, variable power supply and many other places.

Sunday, August 17, 2014

Auxiliary Negative Dc Supply Wiring diagram Schematic

In this Auxiliary Negative Dc Supply Circuit Diagram, IC1 (CD4009) is used as a square-wave oscillator at approximately 25 kHz. CI and Rl set this frequency. C2, Dl, D2, and C3 form a p-p rectifier, which outputs about -3.5 Vdc. This schema should be useful where a small negative dc supply is required, but only positive dc voltages are available.

Auxiliary Negative Dc Supply Circuit Diagram

Tuesday, August 12, 2014

Simple Dc Ac Inverter Wiring diagram Schematic

This dc-to-ac inverter is based on the popular 555. A 555 oscillator schema drives a buffer amplifier consisting of Ql, Q2, and Q3.

The schema operates at 150 to 160 Hz. Tl can be a 6.3-V or 12.6-V filament transformer as applicable.The frequency can be changed by changing the values of Rl and/or Cl.

Simple Dc/Ac Inverter Circuit Diagram