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Author Topic: One for you technical bods...  (Read 1156 times)

Patrick Henry

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One for you technical bods...
« on: March 05, 2012, 01:36:21 PM »

Another item from my nostalgia box...what on earth is this? Anybody recognise it? Anybody know what it does?







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essex2visuvesi

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Re: One for you technical bods...
« Reply #1 on: March 05, 2012, 01:51:03 PM »

That sir is an early electronic speed controller
They used relays at high throttle settings as the electronics of the day couldn't cope.
No BEC circuts or anything like that.

I used to have something similar in my old RC10 car... was top notch in about 198... something
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roycv

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Re: One for you technical bods...
« Reply #2 on: March 05, 2012, 04:34:25 PM »

Hi Essex...  Not wishing to contradict, the reason for the relays, but I think it was because when the throttle was at max, there was still 0.75 volt drop across the o/p transistor.  The relay would come in to bypass the o/p transistor (s) and connect the full battery voltage to the motor.
Thus reducing power losses.

If the circuit was the H circuit then there were 2 transistors in series giving a loss of 1.5 volts.

I built several of the first magazine circuits, the Pompey ESC was the first I tried with an o/p transistor in the tin lid of a small tobacco tin.
Happy days!
regards Roy
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essex2visuvesi

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Re: One for you technical bods...
« Reply #3 on: March 05, 2012, 05:11:02 PM »

I'll bow down to your superior knowledge
I knew the relay was there for a reason
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Patrick Henry

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Re: One for you technical bods...
« Reply #4 on: March 05, 2012, 06:15:19 PM »

So...can we say that this is the infamous Pompey speed controller then, chaps?



Rich
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Re: One for you technical bods...
« Reply #5 on: March 05, 2012, 06:16:13 PM »

They're still in business- http://www.speedmaster.co.uk/

The main thing I remember about ESC's back in the 1980's, was that I couldn't afford one! Anyone remember the Demon speed controllers, they were considered to be the daddy at the time, then Novak came along and ate their lunch. Used to come housed in mysterious black cases.

essex2visuvesi

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Re: One for you technical bods...
« Reply #6 on: March 05, 2012, 06:20:31 PM »

I remember my first ESC cost almost as much as the RC10 it lived in
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roycv

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Re: One for you technical bods...
« Reply #7 on: March 06, 2012, 09:51:20 AM »

Hi, Sorry, I 'lent' the esc to a friend, but he was getting on a bit and forgot and sold the boat so gone now.
(come to think though he was younger than I am now!)

Hi Essex... I did not know what the item was in the first place so fuil marks for identifying it.

I built several kits and then came along the Electronize (kits) ones which always worked on switch on.
regards Roy
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