Titanium ASC1 or ASC-1: Read This Before Buying

[ArloG]

Think about it. The ASC-1 doesn't know if the motor is turning cw or ccw. Becuase the encoder is a simple switch closure. Not a quadrature encoder with leading/trailing pulse pairs.
Therefore. If it were true that you were able to simply put your Harley battery out at the motor. Unhook the to-the-house motor power wires. And give the motor juice. How could the counter know which way to move?
In the ASC-1 MCU. When it commands the relay pair to energize the coils and switch motor polarity and apply power out to the motor.
If it assumes that the actuator is going to move in X direction. The MCU flips into a counts up mode.
When the relay coils are activated to reverse and apply power to the motor. The MCU inverts counting. And down she goes!
You could choose to extend the actuator and have it count up. My choice. Or have it count down when extended just by swapping the motor polarity. The reed switch don't care.

[lme]

Think about it. The ASC-1 doesn't know if the motor is turning cw or ccw. Becuase the encoder is a simple switch closure. Not a quadrature encoder with leading/trailing pulse pairs.
Therefore. If it were true that you were able to simply put your Harley battery out at the motor. Unhook the to-the-house motor power wires. And give the motor juice. How could the counter know which way to move?
In the ASC-1 MCU. When it commands the relay pair to energize the coils and switch motor polarity and apply power out to the motor.
If it assumes that the actuator is going to move in X direction. The MCU flips into a counts up mode.
When the relay coils are activated to reverse and apply power to the motor. The MCU inverts counting. And down she goes!
You could choose to extend the actuator and have it count up. My choice. Or have it count down when extended just by swapping the motor polarity. The reed switch don't care.

Agreed, but just wanted to test EB's suggestion. I'm sure that the hole functionality of ASC is governed by the main chip response to the commands given to the unit itself. As long as an external source is operating the motor, it will not take any action such as to display a count or anything else.

[el bandido]

Think about it. The ASC-1 doesn't know if the motor is turning cw or ccw. Becuase the encoder is a simple switch closure. Not a quadrature encoder with leading/trailing pulse pairs.
Therefore. If it were true that you were able to simply put your Harley battery out at the motor. Unhook the to-the-house motor power wires. And give the motor juice. How could the counter know which way to move?
In the ASC-1 MCU. When it commands the relay pair to energize the coils and switch motor polarity and apply power out to the motor.
If it assumes that the actuator is going to move in X direction. The MCU flips into a counts up mode.
When the relay coils are activated to reverse and apply power to the motor. The MCU inverts counting. And down she goes!
You could choose to extend the actuator and have it count up. My choice. Or have it count down when extended just by swapping the motor polarity. The reed switch don't care.

The test I described is valid for most G box and V box type positioners. The G box and V box type positioners were 40-50 dollars a few years ago, but are a bit pricey today. The pulses or counts go up on these type of positioners anytime the actuator is moved or something else is done to trigger a pulse. The pulses are recorded as counts on the front of the poaitioner when it is powered ON. The counts will be added all in one direction regardless of how the actuator is polarized. The pulse counts may be changed to add or subtract by pressing the east - west buttons on the front of the receiver or by using the positioner remote.

I remember my ASC1 performing the same way where the counts would be added or subtracted anytime the unit was powered on, but apparently my memory is flawed or I had an unusual software installed in it. Pulse counts need to be recorded at all times so any errors in the dish moving may be seen. Cutting the pulse counts off once the positioner has supposedly stopped is a dis-service to the user as any extra pulse count errors will be "unseen" and the operator will be left wondering what the hell is going on.

A stock ASC1 will produce about 100 watts if it is pushed hard enough. You will see this wattage at about 5 amps of draw and 18-20 volts dc output going to the actuator. This amount of power is a bit more than the V box or G box which can produce around 60-80 watts of motor moving power.

I have a Prodelin commercial with a dish weight of about 320 pounds. The dish is in 8 sections, and each section weighs a bit over 40 pounds when put on a calibrated refrigerant scale. The feed and other items puts the weight up to about 350 pounds without the mounting skeleton or polar mount included.

It takes more energy to move my type of dish as compared to most anything else a person will find in a backyard. A 10 foot mesh dish has a dish weight of 60-80 pounds, and some of the homeowner fiberglass will double that mesh dish weight or maybe a bit more. 12 foot home owner dishes will have a bit more weight than the ten footers, but hardly any of them will come close to the weight of a commercial Prodelin. In other words, you can make power modifications to any of the positioners mentioned in this thread, but in most cases, they are not really needed.

The parts shown in post 4 of this thread were installed in my ASC1. These two parts provide 180 watts continuous, with the transformer only being used to supply the low dc voltage needed power the ASC1 The small power supply provides a rated 180 watts continuous power, and provides a steady 35 volts dc while doing so. Peak power is 240 watts, which I have seen a time or two.

In normal operation, it takes a brief surge of about 180 watts to get the dish moving if it is 40 degrees or further from center. But this 180 watts immediately settles down to 100 watts or less. When the motor is moving across the center of the arc, around 40 watts of power is all that is needed. The dish moving is done with a 36 inch ball screw actuator by Venture.

I don't really suggest installing the parts shown in post 4 because they are not needed in the ASC1 unless you want to try to improve the dish moving speed. The ASC1 cannot hold its advertised 36 volts dc when powering the actuator with a ten foot dish attached. It can move the ten footer with east though, but a bit slower than a postioner that runs 35-36 volts dc all the time.

So my opinion here is LME should either fix the ASC1 or simply replace it with a V box. The ASC1 has great advantages when used with a corotor, but for just day to day dish moving, a V box will do that task with ease on most homeowner type dish systems. IMO, the V box type postioners have better software than the ASC1, but they also have less features. I don't recommend modding the ASC1 as shown in post 4 unless there is a reason for it. The only thing most people will see with these mods is an increase in dish moving speed.

[lme]

Thx.
Before your suggested test I will have an outside, mini fan to blow from the opposite side off the transf to eliminate this potential cause.

[el bandido]

You don't need a fan or anything else except a small dc supply. Nothing inside the asc1 will be working except the counter. Of course, the Asc1 has to be powered ON. But the energy to move the dish comes from your portable supply.

[ArloG]

I have 3 ASC-1 controllers 'in the queue' on my bench. 2 with dead MCU's and one displaying LNB is shorted !
The first 2 will definitely need controllers replaced and then programmed.

I would say that depending on the motor itself. The limit switches and diodes would be a great place to check.
The H bridge relays in the ASC-1 don't particularly make a defined 'click'.
But if you suspect that one may be faulty a sure fire test would be to put 2 #194 automotive bulbs in series and then make a pigtail to put across the motor terminals along with the motor.
Motor unloaded. Either direction. The bulbs should be close to equally bright. If they dim substantially in one direction but not the other. Or flicker slightly more dim. Maybe relay contacts. Maybe.

Either direction the dish is directed. The bulbs should light up but not be very bright. Because you're dividing the amp draw between the motor and bulbs.
I've pulled the relays here and the NO/NC contacts easily pass 5 amps with very little voltage drop at 24 volts. Those were several years old.
After a billion "bumps" W-E tweaking sat. positions.

IF the bulbs dim substantially anytime the motor is powered either direction. 2 reasons. The relay contacts could be in fact faulty. Or the motor could be shorting.
If the lamps suddenly get brighter and then you get an error on the display. It's the motor.
Bad brushes. Tarnished microswitches in the motor limit circuitry.

I've seen limit switch diodes short and seen them open.
Open diode, the motor keeps on truckin' in one direction but won't reverse after a switch is tripped by the limit cam.
And the same if one shorts. Except then the motor keeps going after that limit switch is opened by the cam for that direction of travel.

The reed switch in the motor gets ~5vdc from the optocoupler circuit in the controller. The reed switch has to be able to pass current. Not much. To turn the LED on and off in the opto.
Certainly a good test at the dish would be to put multimeter across the sensor terminals and loosen the magnet to trip the switch. It must traverse from that 5-ish volts (switch opened, no magnet close) to very close if not 0 volts when the magnet closes the switch.
But that's not a real test for the switch integrity. Old contacts can provide a 'dirty' signal at the opto. Missing pulses, create extra ones.

The transformer runs very warm. Probably a bit more when the actuator is on a long run pushing the dish. But the #194 bulb test will show any problems.
One secondary winding powers the ASC-1 circuitry and the other is for the motor power circuit.

As EB suggests in #39. I would simply unbolt the motor after moving the dish to the reference position. So you can set it all back up with limit switches aligned for it.
Put the ASC-1 on a table and wire the motor up directly close to it.
Hook up the bulbs to the motor terminals and run it. Give it a good voltage check. Stick a big honkin' screwdriver or a tool in the coupler and drag it down while its running.
Tap the limit switches firmly and wiggle the plungers. Give the motor housing a few raps. Or better yet just pop it open and check the brushes, springs, commutator. Loose magnets.
Everything to troubleshoot up to the controller can be done w/o opening it up or randomly swapping relays.

[el bandido]

Maybe my suggestion was not clear. All you want to do is see if the actuator counts pulses in both directions. Nothing more than that.

Simple steps:
(1) Disconnect the motor leads to the actuator from the back of the Asc1. Leave everything else connected. Verify the Asc1 ON.

(2) Briefly Connect the actuator motor power leads to a dc voltage source and watch the front of the ASC1. The positioner counts on the front of the Asc1 should change immediately when dc voltage is applied to the actuator motor.
(3) Reverse the actuator motor power leads and test again. The positioner counts on the front of the Asc1 should change immediately when dc voltage is applied to the actuator motor.
<End of Test>

In a properly working system, actuator pulse counts go up or down, depending on the direction of dish travel. This test will cause the pulse counts to be added to one direction. The positioner pulse counts do not know polarity of the actuator motor, so they will be counted in one direction only which means the dish tracking will be off. Disconnecting the motor or doing anything else will not change this.


If you were real careful and did several additional steps, you might not upset the dish tracking pulse counts. Most likely though, the dish is already out of sync with the pulse counts as usually that is the case when there is a positioner problem.

[ArloG]

EB. Unless you have special firmware. The counter will not increment unless the H bridge is active.
In no instance have I even been able to increment the counter with just the encoder and motor not energized.. If so, I would have been a happy camper.
Voltage will be present at the sensor terminals. But operating the encoder alone will not change the counter.

I had discussed this with you in the past pertaining to motor coast after the controller de energized it. Those little added gear train movements after the counter is stopped (but armature slows to a stop) add up and create count errors.
Bottom line. Motor is turned off by the ASC-1, the counter is immediately stopped. No matter if you move the encoder manually or power the motor externally.
As an addition. When searching for and peaking satellite positions before storing them. Positional errors for all other satellites that needed global tweaking before adding the brake reduced by a great amount.
This would occur every time the dish was 'bumped' a few counts at a time. Example. Not being able to lock a signal, but you know the satellite must be there from interpolation.
So you move it a little and perform a blindscan to see is a transponder was snagged. No? Move it a bit more and do it again. Until you finally do hook that fish. Then tweak it in.
Wondering if a V box does it differently.

FYI. When I added a dynamic brake inside of the motor housing in the form of a DPDT relay with the NC contacts connected in series with a .22 ohm braking resistor to the brush wires.
Errors from coast immediately decreased by a great amount.
This was to be a provision in the prototype ASC-1 as was the aforementioned (Brian) PWM mosfet in the motor circuit to coast up/down the motor. Which would have been damned nice to keep.

[el bandido]

My apologies if my information is not correct!
I should withdraw from the conversation of fixing the Asc1 as it is not something I normally use. I am certain lme will find a solution!

[ArloG]

And my apologies too. Good intentions, I know. Hope you accept the same.
I'm just a bit peed that the tech. on these is 'eyes only' still even after they were discontinued. Glad Brian is still supporting keeping them working.
They do have similarities with the V box movers. And is why it would be interesting to know if the counter did actually keep active after the motor is shut down.
Kind of seems not though because the counter wouldn't know which way to go since the encoder is pulse/switch closure only. Not a quadrature encoder like your ham rig would have for he VFO.
But. Try to trust me a little. Because my nose has been in deep with the ASC-1 to R.E. it. As far as the circuit and perpheral components go.
A few I've seen here that I worked on have solder pads lifted just because they felt like it.
And there's a bit of dodgy solder work where the various after mfg. mods such as 22 kHz pass-thru and such was done.
Just that I wouldn't jump to swapping relays w/o proper soldering equipment and practices go. Some of the pc board traces aren't very rework friendly.

The motor could be spun all the live long day in one direction on it's own power and counter not change one bit.
Until the E-W or receiver commands it to actuate. When the direction button is released the counter simply stops and the relays open.
In the case of a go-to command from a receiver. The controller doesn't know which direction the motor is running. Just that the encoder is providing pulses.
Break the sensor connection or stop the magnet and an error will show.
I do believe that there is an over current detection circuit though. Because I've seen 'motor stall' here and there. Different from a limit switch notification / error.

Again. My apologies.