diodes

[roo Hawkins]

can anyone give me a ebay link for the right diodes to get for a 6v batt please.

[Peter Balcombe]

Roo,
Google ‘P600D diode’ for the ones being discussed on the recent battery backer thread. Doesn’t make any difference if 4.8v or 6v receiver power system as the diodes voltage rating is way over anything you will use.
Several sellers on eBay.
Peter

[harry curzon]

If you prefer, you can buy a battery backer fairly cheaply, available with normal servo plugs and sockets, or with Mpx green plugs and sockets
https://www.esoaringgadgets.co.uk/index ... cts_id=553

[IanT-White]

Roo , If you need to maximise servo power you can buy from Farnal , low volt drop schotky diodes , ie looses 0.25 volt which is much less than a standard diode , I have used some 10 amp rating 20 volt versions which total success , regards Ian Turney-White

[Barry_Cole]

Roo , If you need to maximise servo power you can buy from Farnal , low volt drop schotky diodes , ie looses 0.25 volt which is much less than a standard diode , I have used some 10 amp rating 20 volt versions which total success , regards Ian Turney-White

Ian,
I may be wrong here, but I think you will find that you only get the low voltage drop at VERY low current, as soon as the current goes up the voltage drop goes up to about 0.8-1.0 volts. That is my experience anyway.

Could you post a link to the ones that you as talking about, please.



BC

[IanT-White]

Barry , I have these diodes fitted in my two thirds scale SF33 motor glider , using a Futaba 14SG TX and two R7008 .
The receivers relay the voltage after the diodes , at the RX,s and initially I had it sending me the voltage every few seconds .
The model has six large Multiplex Rhino quarter scale servo,s plus two Hitech 7995TG 25 kg servo,s plus a further four engine control 20 mm servo,s .
I noticed that the voice indication of voltage ( using four A123 LiFe batteries ) was really constant , slight variation between 6.5 to 6.4 volts what ever I was doing with the model .
Cannot remember exactly which one,s I used , best have a look at Farnal,s website
Regards Ian Turney-White

[Barry_Cole]

Ian,
Assuming you were using the LiFe batteries in two pairs. The voltage from each pair of batteries would be 6.6/6.5 volts, so not sure what you were measuring.

I have the same in both my tugs, and the batteries run at 6.5 volts with the receiver at 5.9 volts after the diodes.

It wold be nice to know which diode you were using??

BC

[Peter Balcombe]

Barry,
Just done a quick google for 10A Schottky diodes & these turned up - also available from Farnell.
RB085BM-40FHTL - Schottky Rectifier, 45 V, 10 A, Dual Common Cathode, TO-252 (DPAK), 3 Pins, 550 mV
Farnell price is 79p + VAT at 10off quantity if I remember correctly.
The datasheet identifies 550mV as the maximum drop at 5A, which is roughly half that might be expected with a normal diode.
Peter

[IanT-White]

I had a look at my spare Schottky diodes and they are STPS15L25D. Farnell part number 9803408

15 amp rated and a forward voltage drop of about 0.25 volts at 10 Amps. The forward voltage drop increases as the current increases above 10 Amps, but still less than a silicon diode.

Regards Ian Turney-White.

[Peter Balcombe]

Yes, they look pretty good Ian