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High Power variable voltage mod for C7042 APB

90940 Views 306 Replies 59 Participants Last post by  Gavin84
How would you like SH type power, the ability to adjust voltage all for next to nothing? Yes? Well read on!

You need
Craft knife
Soldering iron
solder sucker
2x R010 resistors

Difficulty level 2/10 easy enough for teenagers or adults.

Stage one, remove power connector, bend up a leg and refit.

Use solder sucker to remove solder.

Be careful there is a small track on the connector side. If it breaks just use a wire to link from the diode to the side leg.
Prise connector up when all solder has gone

bend up the end leg

Solder back onto board with remaing two legs and solder a thick wire to the bent up leg. Feed wire through 5 volt regulator hole as shown

Stage 2, cut track and solder wire to it
flip board over and with the craft knife cut through the large track shown, cut back and forth until it is cleanly cut. Check with a meter if you have one

Scrape off some of the green stuff and tin the track with some solder. Now solder the wire to the track

Stage 3, add two resistors to double the current trip point
Identify the two resistors R010 in the centre of this photo. Add extra solder either end as shown.

Now solder your new R010 resistors (size 2512) directly on top.

Use a standard C7024 power supply for the untouched connector (this powers the computer)
Use a 0-15V 20-30 Amp power supply for the modified connector (this goes to the power section)

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Good question, analogue mode still functions.

The ability to up the voltage can cause a problem with some cars in analogue mode, it is a "feature" of the standard system as well at full chat, but is difficult to notice.

We are investigating this, it might be that we add a capacitor or take out an inductor.

Digital mode is 100%, and analogue works fine for some cars.
For affected cars you can still have the increased current, but you need to keep volts down to normal.

So not a "numpty" question at all
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Resistors have to be 0.010 Ohms, or 10 milliOhms. Don't use other values.
Size package is 2512
Farnell have them as
RS have them as
Rating is 1 Watt - this is the power that will dissipated from the resistor, not the power we put to the track.
I could do.
I'll dig out some closer pictures for you sealevel
Cut and tinning an area ready for the cable

Position of the two R010 resistors - here I have added solder ready for the additional resistors

Finally with the new resistors in place

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Cut and tinning an area ready for the cable

Position of the two R010 resistors - here I have added solder ready for the additional resistors

Finally with the new resistors in place

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There is a track that is only half a millimetre thick that runs under the connector. It is used for detecting that a connector is fitted (to allow two lane analogue for example). Unless you clean all the solder from the connector legs then as you remove it you are likely to pick up the tiny track with the connector. Thats not the end of the world. Just cut it and discard the track. then when the connector is resoldered in place run a tiny signal type wire from the end of the diode that the track went to, to the connector side leg. I'll show a picture later.
So with a potential demand for quite a lot of these can you get an ex-employee discount??
QUOTE (MrFlippant @ 28 Jun 2011, 19:24) <{POST_SNAPBACK}>you can see they're a little messier,
it was a little tricky getting the soldering iron onto them
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It is easily reversed if you want to put the APB back to standard.

Let the dust settle? Too many mods? I thought people wanted this one...
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Hey, you can get dual lane analogue with PB-Pro SH, you just need a relay and a few wires... I did a thread somewhere.
I've got 8 spare resistors so the Riko APB+ service is open
I have a list of


so thats 8 resistors so the list is now officially shut
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No its not easy, it involves soldering to the ends of tiny surface mount resistors. You have to have a fine tipped soldering iron and good eyes (or a jewellers eyeglass like me)
OK, close up of the track replacement. Wire runs from the end of the diode by the connector to the middle leg of the connector. Easy!
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It is NOT worthwhile doing unless you have a big power supply and/or variable one.

This mod separates the power section, so where before you had both PSUs feeding it now you only have one, but of course without the limitations of before

So don't do it and just use C7024's, as you will only get half the current.

Yes, Mr F that is the other side of the wire, the photo is not brilliant but essentially I added solder onto the exposed leg of the connector, and soldered the small wire to it.
I'll take that back, if you do this mod and use a standard psu tyou will get more speed as the power goes unchecked to the rails, compared to a standard APB it is +2 Volts! So you can more for less. Super! Super Advanced Power Base! SAPB
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I'd need to get a supply of resistors, but if you twist my arm...
Well its true, and you are right. It will give more speed, but if you want to use 4 cars then you need a bigger than standard PSU to give the oomph (can't spell oomf?) welly!
2 Amps insufficient

I bought a 12-15V 30A supply for £25 so you need to keep searching...
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