AMT Autoscale power supply?

[monkfe]

Hello All, I picked up an old AMT Autoscale that has no power supply with a press purchase. I've done a google search and have found answers for just about every conceivable power supply one could have as apparently Lyman changed it a bit when they purchased the right to it. This unit uses an old school style 1/8 stereo plug. I used a universal Radioshack power supply at 9 and 12v. The optical sensors light up, but the motors only turn a little and I don't want to do any damage to it so if someone has one of these and can let me know the particulars that would be great. Attached are some pics of the internals.

[EDG]

I have 3 Autoscales.
One is an original brown AMT with the stupid 1/8" stereo jack. That means you have a hot plug exposed to short out. Naturally the instructions say to leave the plug in the Autoscale all the time.
I bought the AMT model less power supply and Lyman sent me the later model power supply with the protected plug. So it would not work. I spoke to Lyman and they sent me a universal power supply.
The universal was a Chinese made version with several different connections and 7 different voltages. It also has a selector to change the polarity.

My orange Autoscales have the larger jack for a protected power plug.
The Lyman power supply is 9 volt DC. it has a switch for 120 Ac or 240 AC.
The center conductor is positive. The outside conductor is negative.
Current capacity is 200 mA.

If I had mine apart I would change the jack to the later style that is protected from shorting.

With the beam out of the housing the the motors should run continuously. With the beam in place the fast trickle motor shuts off on approach to zero. The slow trickle motor shuts off at zero.
The adjustment knob allows you to adjust to prevent aver shooting. The over shoot adjustment shuts off the motors earlier or later. You just set it by watching the beam. If the fast motor run too long the pan will be loaded past zero. Set knob to shut off the fast trickle just short of zero. The slow trickle will run until the zero sensor stops it on zero.

The universal power supply that Lyman sent me for the old AMT AUTOSCALE is a Franzus brand model BB-333D.
There are 4 plugs plus a 9volt battery type connector.
I have it set to 9v and + polarity for the center conductor.
Amps = 300mA.

[monkfe]

Thank you Sir! Seems to be a problem with the scr trigger circuit. the motor runs when I have it hooked directly to 9v . I 've changed out the power supply connector as you suggested.

[abunaitoo]

I have two Lyman and one AMT.
One original Lyman 9V DC power supply.
Other two have aftermarket.
To me these are the best powder measures made.
Not finicky like the digital.

[EDG]

The gun buying people in this country are almost backward in their in their reluctance to adopt anything new.
They took about 30 years to adopt interchangable shotgun choke tubes. They never did adopt the excellent Autoscale.


They seemed to have been too expensive and were not an attractive gadget compared to later digital garbage. My Autoscales have the same beam scale as the Ohaus/RCBS 5-10 scale.
They dispense to .1 grain automatically. The major complaint I have heard is they are too slow with large powder charges. That is no big deal to me. I just set 2 for the same powder charge.
I have 3 now and I will buy more when I find them cheap.

If you buy one learn how it works so you do not have to depend on the bozos at Lyman. They cannot even trouble shoot the simplest problems.

They can jam stick powder grains end to end to lock up the tricklers especially with the giant kernels of SR4759. If you have these jams it is easy to correct with a needle file in about 2 minutes. You don't even have to disassemble anything.


I have two Lyman and one AMT.
One original Lyman 9V DC power supply.
Other two have aftermarket.
To me these are the best powder measures made.
Not finicky like the digital.

[abunaitoo]

A while back, I had help from a member here slowing down the fast tube.
With some powders it would feed to fast, and over shoot the weight before it stopped feeding.
Installed a variable resister on the fast motor to slow it down.
Works great since then.
When I can find some spare time, I'd like to mount the resister so that I can adjust it without taking it apart.
I haven't had to adjust it, but it's something to do to make it better.
These measures are great.
I'm surprised a new version hasn't come out.
I'm sure the patent has run it's course.

[EDG]

The black knob is an adjustment to prevent the fast feed from over shooting.
A variable resistor on both tricklers would be a nice improvement. With today's electronics you could probably have approach to zero software give you the best of beam and digital scales in one faster unit.

[abunaitoo]

I had the black knob all the way to slow. It still over shot.
I was going to open it up and see if i could open it up above the eye a little more.
With flake powder I would like it to turn off the fast tube later.
The slow tube seems slow enough.
By having an adjustable fast tube, it would make it faster.