Re: Stern REAL Knocker kit available @ Pinball Life

The output at the coin counter is 5VDC, not enough to drive a 30 or 50V
coil with any force.

Andrew

cfh@xxxxxxxxxxx wrote:
seymour-shabow@xxxxxxxxxx wrote:
leon wrote:
For those who want to give it a try to make it yourself , it can't be that
difficult eveything is already there!!

The output J7 pin 10 is foreseen to drive a coin meter and this connector
arrives just above the tilt plomb. You will find it floating there with
nothing connected .It is a three prong white connector , only two wires are
inserted a red and a purple/grey one , The purple grey one comes from J7 pin
10 as the driver transistor behind this wire is a TIP122 wich can drive 8amp
this may be at the low side, so you will need to add a TIP36C as exta driver
and connect there the knocker coil ;
How to connect a TIP36C at the excisting Tip122 ??

The Tip122 can't drive a knocker on its own? That's what bally, stern,
and williams used to use on system 7, mpu35, etc. - Granted on the
williams machines this transistor often burns..

Well a couple things.
First on Stern games they aren't using a TIP122.
The are using logic level driven FETs. So can a
FET drive a knocker? Well sure it can, but there are
some things to think about.

first is the knocker 30 volts or 50 volts? I don't
know if stern is still using a 30 volt buss anymore.
They did this back in the 'old days' when the DE
CPU board was a direct copy of Williams' system11.

System11 started out with 30 and 50 volt coils.
Flippers were 50 volts, most everything else was 30
volts. Then they started using 50 volts for more and
more coils (like up kickers and the such). Hence
the Auxiliary Power board which had TIP36 transistors
to drive the higher voltage coils.

Eventually with WPC williams of course abandoned
all 30 volt devices and just used 50 volts for coils.
I would be thinking that Stern did the same thing.
but i would have to see the schematics.

But anyway, can a FET drive a knocker? Well since
this replaced a coin counter, and most coin counters
are 12 volt devices, maybe not. Again i would have to
see the schematics and see what kind of FET is
driving the coin counter (and now the knocker).

.

Relevant Pages

  • Re: Stern REAL Knocker kit available @ Pinball Life
    ... The output J7 pin 10 is foreseen to drive a coin meter and this connector ... The Tip122 can't drive a knocker on its own? ... first is the knocker 30 volts or 50 volts? ... System11 started out with 30 and 50 volt coils. ...
    (rec.games.pinball)
  • Re: Stern REAL Knocker kit available @ Pinball Life
    ... The Tip122 can't drive a knocker on its own? ... System11 started out with 30 and 50 volt coils. ... driving the coin counter.. ...
    (rec.games.pinball)
  • Re: 3 Phase - 3 Phases
    ... When the coils are excited with 3 phase, the coils, in effect, take turns using that bridging part of the core. ... Either their fields around the loop through those two legs adds, so that that loop has twice the rated peak flux, or they buck each other, putting twice the normal flux over through the third leg. ... at least you get the same volts per turn and it still acts like a transformer. ...
    (sci.electronics.basics)
  • Re: Ignition Coil Interrupter
    ... coils and the like from them. ... hundred volts AC. ... metal-can coils with the big black bakelite insulator on top. ... diode to keep the fet substrate diode from conducting. ...
    (sci.electronics.design)
  • Re: 3 Phase - 3 Phases
    ... > that have coils on them that carry flux from more than 1 coil. ... putting twice the normal flux over through the third ... at least you get the same volts per turn and ...
    (sci.electronics.basics)