ante

The most common UPS:s where I work just have trickle charge at 27.6Volts and these batterys (Dual Panasonic 12V 14Ah) is changed every five years. When measuring voltage and voltage under load (40 A for 15s) on these recycles only 5 out of 50 show any signs of degradation. However there is a charging method called reverse pulse charge that can be used if one considers idling a threat to the battery. Sometimes a high current pulse is used, once every hour (or at any suitable interval) a high current pulse is pushed through the battery causing the voltage to raise and stir the electrolyte. The length of this pulse can vary as well as the strength. The number one reason for batterys to lose there capacity is sulphating and one cause for this is the separation of the acid in the electrolyte. This means that on the bottom of the cells the gravity of the electrolyte can be 1.28 and on the surface 1.22. The sulphating starts at the bottom of the cells and eventually causes shorting of the plates. This will not happen if you can stir the electrolyte from time to time. On some bigger batterys they are even pumping air through plastic pipes that discharges at the bottom of the cells during charging. This is like the pumping of air in a fishtank only it

sasi, Well the high point can be 13.75V without losing any water and the low point depends on how long you want your battery to live. Best tip here is the manufacturers recommendations for maximum discharge (minimum voltage). An alternative is to trickle at 13.75V and never shut it down completely.

Greg. What

I did not analyse the complete circuit but if the battery is 12V then the LM7812 will not work here.

I don

Yes, I figured that was the case after I looked around in the Blanchard place. You just rest for a few days and it will pass. Pour some good stuff in your tea or coffee and you will feel much better shortly. It

Is the residual voltage a problem; is the production of hydrogen greater than the idle consumption? So, the P-channel is hard to get at your location. The Blanchard site H-bridge has P-channel AND N-channel MOSFETs. I agree this gets a bit complicated compared to an ordinary bridge. Maybe someone else reading this have a suggestion. You can use a 555 instead of the ICL7660 to create a low current negative supply if you need one. How frequent must the electrodes change polarity to keep nice and clean? I know this is answering questions with questions but I like to know as much as possible to give you the best answers I can come up with.

Rhonn, Here are some clues: http://members.misty.com/don/f-dim.html

Hi Rhonn, How much power do you need (W) ?

Kevin, No not PWM, but phase control. If you have Power Point installed in your computer, here it is: http://www.eas.asu.edu/~karady/360_stuff/Lectures/360_Topic_7_Power_Electronics.ppt If not check the PDF, sorry that the pages are sideways. SCR_phase_cont..pdf

Kevin, That

Audioguru, Oh, I forgot to mention I have a ton of RFG50N05 so it would be nice if they were usable . Its not a must I can get some new if required.

Audioguru, Sounds good, I am looking forward for a schematic to be posted sometime in the near future.

Sasikumar, If you post the circuit you

I

Audioguru, I like an inverter for car use and I need it to be sine wave output 230-240VAC 50Hz @ 300W. It would be very nice if it where variable 0

Amen!

Audioguru, Only to cool guys! 8) Ante ::)

Thanks Audioguru, I better look elsewhere for a transmitter circuit, I couldn

Why is this transmitter called 4W it can

Audioguru, What

Audioguru, The man says

Sasi, Look good, a few points: Why not use a 230VAC changeover relay, this will lower the cost and component count (one transformer, one rectifier, and one cap). At least remove the capacitor to get a quicker changeover? But don

Rhonn, Yes 100VA is almost 100W but you can

Quantum, I found a site for you with nice experiments; there is a small problem though. Or maybe not, can you read German: http://www.hcrs.at//MIKRO.HTM Ante ::)