Few months ago I ordered ARTESYN - NLP40-7629J - SWITCH MODE POWER SUPPLY from element14. Including shipping and taxes, it took nearly Rs. 3500 (~USD $70) to reach me. Have a look at the SMPS in the pictures below. My wish was to make a nice lab power supply for my workshop, and I didn't want to use transformers again this time and wanted to switch to switch mode supplies. For this, the most obvious and relatively cheap choice was to use a Rs.500 (~USD $10) computer SMPS, but I decided to go Continue reading [...]
Bench PSU made by ARTESYN NLP40-7629J SMPS
Few months ago I ordered ARTESYN - NLP40-7629J - SWITCH MODE POWER SUPPLY from element14. Including shipping and taxes, it took nearly Rs. 3500 (~USD $70) to reach me. Have a look at the SMPS in the pictures below. My wish was to make a nice lab power supply for my workshop, and I didn't want to use transformers again this time and wanted to switch to switch mode supplies. For this, the most obvious and relatively cheap choice was to use a Rs.500 (~USD $10) computer SMPS, but I decided to go Continue reading [...]
H Bridge inverter power stage with passives
The above circuit I got from replies from edaboard. I had created a thread there on how can I drive a 2 pin primary transformer with H bridge configuration with my SG3524 PWM circuit. I got many replies to use dedicated driver ICs, suggestions to use floating high side gate driver, etc. But I simply needed a solution to run it with circuit made of passive and discrete components and alertlinks gave me this circuit.
This circuit generates a 24V supply from the 12V battery voltage and makes the Continue reading [...]
OSSDAS v1
![000_0004[1]](http://circuitsdiy.com/wp-content/uploads/2012/04/000_00041-150x150.jpg "000_0004[1]")
The PCBs for OSSDAS came yesterday by post from SeeedStudio.
This is the completed board.
Looks like old firmware was still in the microcontroller. The board just booted up after soldering with old software. Now it's time to work on the software.
I'll upload all project files to github once I learn how to use it. :) Continue reading [...]
LM317 regulator board PCB making
LM317 is the most used and easily available adjustable voltage regulator. Here I've designed a simple PCB for the regulator with surrounding diodes, capacitors, resistors, etc. In this board, the voltage adjustor connector is given into which a potentiometer can be attached for variable supply.I've designed the board from the given application circuit in the LM317 datasheet.
Download Eagle design files.Here I've printed the front and back of the PCB's layout mirrored for toner transfer process. Continue reading [...]
How to repair dead mobile charger
The above image shows the inside of a typical mobile charger. These chargers can burn anytime and then they need to be replaced or repaired. Fortunately the repair process isn't much hard as there are few components to check if the charger is dead.
The common things that usually burns/cuts is the transistor, the 1/2watt resistor in power mains line, and occasionally few of the 1/4watt resistors. In this case the transistor was open. Note that the board had 120A transistor. And we can replace it Continue reading [...]
Step by Step: Make an Inverter’s power stage (MOSFET)
Here I show how to make the Power stage of an homemade inverter. I'm using the following,
Old UPS transformer
2x Alluminium Heatsink
2x N-MOSFET (IRF540N, P55NF06, B150NF55 etc)
Screws, spade terminals, wires, etc
First we need to place the MOSFETs in the heatsinks in appropriate place so that the heat tab i.e, metal part of the MOSFET body is as close to the mid area of the heatsink. This way more heat will be dissipated by the heatsink.
Now we look at the transformer salvaged from Continue reading [...]
Convert square wave Inverters to sine wave Inverter
There's pretty easy to make squarewave inverters' circuits in the internet. But to run most load like fan, TV, etc you need to have a sinewave inverter. Making sinewave or near-sinewave inverter is more complex and costly. But we can also convert squarewave inverters to sinewave inverters. A LRC resonant circuit is needed for this. The values determine the output frequency and waveform.
For a 50Hz 150V square wave output to become 230V 50Hz sine-wave, you need the above circuit connected to the Continue reading [...]
DIY LED driver for 5Watt LEDs, 12V strips from 100-240 VAC
I got many requests to provide guide to build simple 230V to 1,3,5 Watt LED driver in response to my simple led driver diagram. So, below I'm writing an article on making of a high power LED driver circuit. The below device is able to run upto 5Watt LEDs from the LED supply line and 18Watts of 12V LED strips.
I've made the following article specially for people new to electronics so there is many small steps included which may look like verbose in view of a pro technician. Also since the following Continue reading [...]
Subwoofer Lowpass Filter using uA741 Single Op-Amp Ic
This is the simplest Sub woofer Low Pass filter Circuit using uA741 single op amp ic.The circuit is very low cost with respect to their work. The cut off frequency of this circuit is 25Hz to 80Hz maximum.
Using this circuit , you can easily design a 2.1 Sub-woofer Speaker System at your own Home. The circuit contains very few components.In Pakistan, the cost of this circuit with PCB is Rs:45
The same circuit is working in my own hand made sub-woofer system.So Try this
Parts List:
R1,R3,R4 Continue reading [...]
OSSDAS rev. beta
This is current revision of the OSSDAS project. This new beta design is as follows. After few days this design will go to a board house. Now just touching it for perfection. Any features/suggestions are welcome.
Features added:
Current sense through even lower valued resistor and using op-amp to multiply the very low drop voltage. Symmetrical to a low side CSA.
Integrated charging control. Charging path from solar panel to battery goes through CSA, FUSE, DIODE, INDUCTOR, and a MOSFET. Continue reading [...]
