delabs Circuits

Showing posts with label SMPS. Show all posts
Showing posts with label SMPS. Show all posts

Saturday, August 13, 2016

CFL Lamps and Simple Inverter

Kindly help me make one issue devoted to------ CFL Ballast Circuits----viz. circuits to drive a 5/7/9 / 11W....upto 18 watts CFL from a 6 volts / 12v DC battery, or Solar Panel,(or 220 volts AC Mains) Believe me, this is a crying need ,of the day, all over.

The market is flooded with poor Lanterns, that work for 2 to 4 months then they can't be repaired even. Some makes are either high-cost/high Quality, or low cost - low quality. Custom Ballast ICs coming nowadays are no use, because they are obsolete in 4 to 6 to 12 months..

Also, the circuit must have a (SMPS) power supply too, with overcharging * under voltage cutoff, as the CFL goes black, on being switched at low voltage.

mail from SRM

I can try to help you, Please Explain your need. Which way do you want me to help you.

CFL Lamps and Simple Inverter

A simple inverter for florescent lamps
This inverter is very easy to construct, reliable, and even powerful enough to light up a 15W florescent tube (if you cool your transistor well). The only hard-to-find piece of this baby is the so-called yellow inverter transformer

Oh no! Not Another CFL Inverter
This one’s a beauty. It will drive multiple CFLs without the need for heatsinks on the MOSFETs. Fit heatsinks and you can run even more, up to a total of 100W.

I can design with some SMPS type chips. Overcharging is only in Emergency Light Lamps. CFL's do not have this as they work on 230V. Make a more detailed specification. Then I can think more about it.


the problem is NOT that simple.............. problem is to RUN a CFL bulb, from a 6v/12v DC battery. Again, the problems are-----

1)Efficiency, of energy utilization, in the battery
2)Without using Custom LSIs(which go obsolete Unavailable in 6/12 months time and are replaced constantly ,by ever more sophisticated costlier models
3)Blackening of the ends of CFL, near electrodes
4)LIFE of CFL(supposedly--12000hours for European CFLs;8000hours for Advts;5000hours maybe ,reallife...
5)Simple Circuit, which can be easily repaired in the field, by non-technical people in village/small towns.
6)Low Cost--so, even the poorest person can buy use it
7)Fast Charging , of the Battery(out of 24 hours--likely to be used for 4/6/or 8 hours .So, it has to be charged in the balance of 24 hours...
8)Low Battery High Battery Cut-off; to prevent damage to battery CFL
9)Compliance with the Basic Ignition Data, furnished by CFL manufacturers.These are like----filament voltage,Ignition Voltage, Current etc

mail from SRM

Tuesday, February 17, 2015

Single Chip dual power supply

message: Hello, I want to know the single IC which can provide Both + V and -V from a single +Vin supply.. I need this for my dual supply opamp.Reply me as soon as possible. -  Thank u.

Mail from KM

There were chips, but now obsolete as most use a smps circuits. you can try this RS232C Level Converter it has -10 and +10 that can power low-power cmos opamps and chips.

or use LM7912 and LM7812l you will need two chips, there was a LM326 but not now. See Linear Regulated Dual Polarity Power Supply

When a Inverting Opamp Configuration is at a steady state, we say the Inverting Input is at a Virtual Ground. That means it is at 0V w.r.t to the dual power supply ground, but it cannot drive or draw any current. It is at a high impedance, but still at 0V. When you buffer this 0 V, you get a low signal ground for a opamp supply. Opamp generates Virtual Ground. See this a Isolated dual power supply from 5V

Dual Polarity Power Supply


I am very happy to see ur reply.I am appreciating ur job. Ok.. Ur information is most useful for me.. We ill meet with another problem.. Thank u..

Mail from KM

Monday, January 19, 2015

Mystery of the Switching Paradigm

I was not able to solve a issue with an Enthusiast who tried building a Power Circuit Design of mine. It was a design that was not complete in documentation. I had just put it online for people to study. Marin built it and went thru a lot of trouble.- This was in 2005-6

Story Starts Here -

I built switching power supply with SG3524 (project del20020) from your site

It is working, but not good :-( Voltage and current regulations are very bad. I connect  stabilized 13V to input, and from another stabilized power supply I connect 12V for SG3524 and LF358. For testing I use mosfet BUZ11, and various ferrite inductors, but results are bad.

On output I cant get more than 6V, and output 470uF elco sounds like "bzzzzzzzzzzzzzzz"   I checked, and rechecked all connections several times, but everything is like on your schematic diagram.   Could you tell me if your schematic diagram has any bug?

Did you built any working switcher with this schematic?   Maybe is problem in inductor. Is it critical? I tryed with few toroid and ETD44 EI core with 4 to 40 turns of wire, with no luck :-( Which corre and numbers of turns do you suggest?

Power Supplies Section

Mail from Ing. Marin Antic

Mystery of the Switching Paradigm

delabs Reply

This i  a 15 year old circuit and working well, there may have documentation errors. i will look at it when i have some time. meanwhile troubleshooting is better.

The circuit itself can have errors, and then while you breadboraded there could be mistakes. the inductor is required for proper working around 50uH you will need a LCR meter or make a test jig.

Where is the bzzzz sound coming from is it a lose core of inductor vibrating. you said voltage is 6V does it give good curent, is load regulation good.   the input power needs to be 3-4 volts more than what you need a t output try 15V and also does input power suppy have good current rating like 5 is the input power supply able to able to drive the load you want. probably the input power supply may be loaded.   see for any heating parts. the problem is in the connections or the feedback path. look around the LM358, you can chat with me online. i will certainly try my best to help you.

I think that your schematic can't work good. Do you have continuous voltage and current regulation from 0-12V and 0-5A on your swicher? I think it is impossible with this schematic...

When I modificate sg3524 output stage to the mosfet, I got full voltage on the output not only half like before. But voltage regulation is not continious. Now I can regulate voltage only 6-12V. 0-6V not working. On 6V is step, and then continious regulation.

 I tryed many modifications on connecting LF358 to the output, an now is working. Not very good, but good :-)   Current control is not working ok. What do you think to move current sensing on positive output, not on negative?

mail from IMA

delabs Reply

Just check these points.

vary inductor air gap, make it also more like 100uH. Keep current limit to minimum and try. Or to locate problem disconnect pins  4-5 and then connect 4-5 to ground. Now current control has been disabled, see if vtg control and load-line regulation ok.   C2 and R10 fix frequency of SMPS 2.2k and 10nF plastic, verify.   Mosfet drive part may have to be modified bit as per circuit attached.   try all in the order show or as your understanding..

(see a application note below, not the circuit being discussed but the chip)

sg3524 smps

Saturday, April 19, 2014

Winding Transformers and Coils

i would need your help in designing transformers for rechargeable lamps. i really don't understand what the dots in front a coil stands for. all help (including pictures) would be really appreciated. my own just packed a few days ago and i would love to recoil the transformer.

mail from LA

You will have to do a lot of study in the internet, and experimentation too. Transformer winding is a specialized profession not a hobby at all. You can wind some coils or small signal transformers, that is ok. Please do not try to wind mains or 230/110 V transformers at home.

Winding Transformers

I can only give some tips, precautions and techniques to a winder. study these links....
I have put the link of a page but see all the pages of the website. The Dot polarity in a transformer stands for the direction of winding relative to each other. The Direction of winding could be clockwise or anti-clockwise.


Tuesday, March 11, 2014

Lighting a LED String - Serial Drive

Hi there, my name is steve. I would like to ask you about the best way or the most efficient way to supply LEDs. there are 36 small LEDs or 72 small LEDs (5mm).

could I just put then in series the 36 LEDs and a diode, resistor and plug in to AC power line (110)

(An email i got some time back)

Answer - Lighting a LED String - Serial Drive

Remember that the LED for lighting or otherwise needs to be protected from over current on Forward Bias and High Voltage connection in Reverse Bias.

That means you could use a 3 A Diode like 1N5408 to prevent wrong polarity connection. Then all you need a constant current source with a voltage output a little above the product of the Number of LEDs and Forward Drop of a LED.

5 LEDs in Series with a forward drop of 3 each means 5 x 3 = 12. You need a 15 Volts Regulated Supply with a current limit of around 30mA or more. See the LED datasheet. Go beyond limits you lose your LEDs the same day or months later.

Use SMPS designs for smaller sizes and it has to be Robust to Mains Power Supply Variations. Use a Surge Protection Assembly from a Reputed and Quality Supplier. (this surge part spoils the reputation of your Lighting Product and affects the entire LED lighting Business)

Read these pages to learn more....

The Perfect LED Light -  by Garry Petrie

"The perfect LED light is designed for cavers who want an efficient, uniform and constant bright light for caving. This article contains some very specific technical information and it is assumed the reader has a basic understanding of electronics. To build the light, the reader also must have some experience soldering, drilling, wiring and cutting small objects."

The Perfect LED Light -  by Garry Petrie

A linear Constant Current LED Lamp Dimmer

"This simple Linear circuit provides continuously variable regulated current (~25-400mA) from a 4-6 Volt source.  I chose a linear design for simplicity, reliability, ease of repair, and to avoid switching EMI in my Cave Radios.  The circuit requires only 0.2V headroom above the parallel LED Array voltage to provide regulation at maximum current. "

A linear Constant Current LED Lamp Dimmer