Page 1 of 2

Without a battery

Posted: Sun Nov 08, 2015 12:40 am
by thackers
Is it possible to run a koso tacho without a battery? Obviously I'm not electrically minded so if there is a way, simple explanations and links would be great. Thanks

Re: Without a battery

Posted: Mon Nov 09, 2015 6:37 pm
by wack 63
I wonder if a 5 pin Vespa reg or Varitronic gives out enough to run a gauge? What about a Modcharger? Thinking about it , if it's the round type tacho that sweeps when turning on then it needs a permanent feed to keep it's settings.

Re: Without a battery

Posted: Mon Nov 09, 2015 6:52 pm
by thackers
Hi Lloyd, it's a digital readout. I've done a forum search and found someone who had the same problem and he used a "bridge rectifier" or something to convert AC to DC or the other way around, i'm not sure. Another forum member gave some links to ebay items but it was back in 2010 and the one who asked the question hasn't been an active member since.

Re: Without a battery

Posted: Mon Nov 09, 2015 10:06 pm
by wack 63
It would be handy to know if you find a solution Dave.

Re: Without a battery

Posted: Mon Nov 09, 2015 11:07 pm
by carlos fandango
koso do a small rectifier , ive used one in the past and velcroed it to the inside of my headset
http://www.digital-speedos.co.uk/12-vol ... -132-p.asp

Re: Without a battery

Posted: Tue Nov 10, 2015 10:57 am
by molibdimum
Sorry to rob your post Thackers but I wondered if this Koso rectifier thingy would help to get a better sound from the standard Lambretta horn??

Re: Without a battery

Posted: Tue Nov 10, 2015 12:49 pm
by EddieStone
molibdimum wrote:Sorry to rob your post Thackers but I wondered if this Koso rectifier thingy would help to get a better sound from the standard Lambretta horn??
Doesn't look like it. It handles about 6W and a horn would draw a lot more power than that. You could try and put a bridge rectifier (four diodes) in the horn circuit and replace the horn with a DC type. That would stop it sounding as buzzy. You'd need some hefty diodes though, to handle the current.

Those DC converter thingies are pretty easy circuits build yourself - components would cost about £3. I'm happy to have a go at making one if someone wants to try it?

(As long you're not in a rush - A lot of my time is taken up with the Li in the lounge....)

Re: Without a battery

Posted: Tue Nov 10, 2015 3:18 pm
by vicvega

Re: Without a battery

Posted: Tue Nov 10, 2015 3:26 pm
by EddieStone
vicvega wrote:http://www.amazon.com/Autek-Converter-R ... B00KM0U7RE would this do the same thing?
Yep. That has a lot more power capability than the other one - it can supply up to 3A and 24W, compared to the 0.5A/6W of the Koso.

Re: Without a battery

Posted: Tue Nov 10, 2015 3:30 pm
by EddieStone
hang on, though - it needs 15V minimum, which a scoot is not likely to generate. Is there one that has a lower minimum voltage, say 10V or so?

Edit: This would do it: https://www.superbrightleds.com/moreinf ... dule/1725/