[GreenKeys] M28 using 20ma

[Thomas Tillson]

Yes, the motor control also has the loop circuit is series with the loop and they also have to be wired for .20.
 I was assuming he did NOT have the motor control.

TT
In a message dated 7/28/2019 7:21:55 AM Eastern Standard Time, steve.n4tty at gmail.com writes:
The D block is mentioned in Note 5 as well.  The D block is labeled Motor Control.  How exactly does motor control enter into the picture?  I'm guessing it is watching for idle line current so it also has to be adjusted for 20ma operations?
And the note says make two parallel connection from A1 to A2.  Was this so you would have the two straps handy if you wanted to go back to 60ma?  If so, why not three parallel straps on the D block?

Steve G./N4TTYSent from my iPhone
On Jul 28, 2019, at 6:57 AM, Thomas Tillson <til128 at aol.com> wrote:


FYI-

Attached is the wiring diagram for the LESU modifications for running 20 mA.
Note the change IS on the "A" block and read note # 5.
Tom WB2TTY
In a message dated 7/28/2019 6:35:36 AM Eastern Standard Time, steve.n4tty at gmail.com writes:
To change the machine from 60ma to 20ma, on my machines, I would make a couple of wiring changes on the "A" terminal block in the LESU.  That is where the wiring from the "C" block makes it's transition to the connector that plugs into the typing unit.  If memory serves me, and lots of times it fails me, that is annotated as the "R" plug on the schematic of the wiring of a M28.  I could be wrong about the "R" but I'm right on about the "A."  On all my machines so far anyway.  Now if yours has been modified multiple times in the past, all of this might not be of any use in your case.  It should however match what you would find on a KSR or ASR schematic.
I could possibly be prodded into sharing a home made schematic that shows just this portion of the selector  magnet wiring from the "C" block to the "A" block and then on to the "R" plug.
This is how I have done several KSRs and I'm currently starting on an ASR, so I know the Reperf is going to have to be fit into the picture.
The thought just occurred to me, if you had the line relay, couldn't you run the relay windings with the 20ma loop and use the internal 60ma loop for the mags?  Providing of course your LESU has its own 60ma supply.

Steve G./N4TTY
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