This weekend's project - Remote motorized volume control

I love my vintage systems but there is no denying that it's a PITA when the phone rings and I have to run over there and turn down the volume. A remote volume control, that's what I need!
So here is this weekends project, a remote motorized volume control. Out of pocket costs - zero. All parts were lying around here and / or salvaged from junk units.

I removed the motorized volume control from a defunct Sony CD changer along with the 4 RCA connectors. Currently the remote is wired but I'm ordering a 2 channel RF remote from an ebay seller (~$18 shipped) to complete the project.
The circuit is quite simple; change the polarity on the voltage applied to the motor (6VDC) to change direction. There is also a simple 2-lead / 2- color (red/green) LED to show volume up (green) or down (red) on the unit itself. The motor appears to have a slip clutch in it so that if power is applied when it is at the limit current draw doesn't go up and there is no apparent damage.
The wired switch I'm temporarily using has a filter setup so that as you move the lever it is either red or green. I know it's a unique switch but any center off, momentary contact DPDT switch should suffice. I still need to enclose the switch still.
This can be inserted in a tape loop or in place of the pre out / main amp in jumpers found on many vintage receivers.

JimB

Very nice idea, nicely executed! :thmbsp:

Adding it via the tape monitor or pre/main jumpers means you don't alter the original unit at all, plus you can move this RC between different units as the mood/need strikes you. It does add another 'component' in the signal path, but the trade-off is that you get your remote. Next time I'm thinking of passing by or discarding a unit, I think I'll check and see if it has a remote function that can be removed and used this way. Thanks for sharing this!

smart young feller, arncha w1? nice idea...

Well done. I have exactly the same problem with my vintage stuff not being remotely controlled. However Engineer Mr. Dave (me) is fleshing out a concept in his mind that will be pure mechanical versus an interjected electrical solution. Some sort of mechanical rubber friction roller wheel on the volume control will be involved. Stay tuned..

In the meantime enjoy your new-found couch potato status

Hokieman said:

In the meantime enjoy your new-found couch potato status

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You don't mean found, you mean earned.
Why not just take an RC car and interface the rear tire with a belt? And then hook it up to a clapper.
JimB

I love seeing stuff like this. Great!

w1jim said:

You don't mean found, you mean earned.
Why not just take an RC car and interface the rear tire with a belt? And then hook it up to a clapper.
JimB

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It would be much easier to just use the Servo from a R/C airplane like one of the Cox foam R/C planes they have to be cheap used on eBay. Make a pulley to replace or glue to the servo arm then just string a rubber O ring or short TT belt of what ever over your volume knob.

Great idea you made!

Mark W. said:

It would be much easier to just use the Servo from a R/C airplane like one of the Cox foam R/C planes they have to be cheap used on eBay. Make a pulley to replace or glue to the servo arm then just string a rubber O ring or short TT belt of what ever over your volume knob.

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Have you ever tried this Mark?

I've often thought about doing exactly that, mounting the servo to a board that the component you want to control can sit on top of rather than mounting it to the component. It could be used with a variety of amps with nothing more than a change of belts. :scratch2:

EDIT> I didn't mean to start a thread hijack. The original poster has a great idea and has done some nice work there!

Chazb11 said:

EDIT> I didn't mean to start a thread hijack. The original poster has a great idea and has done some nice work there!

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Oh, not a problem. It all fosters discussion along similar lines (oh look, a bunny).
Just imagine, you could hook up all of your equipment to overhead belts like in an old factory.

Very cool!

Where did you get that illuminated DPDT switch depicted in the last two images?

ablethevoice said:

Where did you get that illuminated DPDT switch depicted in the last two images?

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I salvaged it off of a funky control panel that I picked up who-knows-where. I replaced the incandescent bulb with a white LED. This switch actually has 4 poles with each making contact while resting and then breaking 2 of those 4 contacts when actuated. A simple DPDT switch would suffice but I didn't have a center off with momentary contacts in the other 2 positions. I have a whole lot of miscellaneous parts on hand here. I'm certain the switch shown is no longer available and if it were would cost plenty!
JimB

Mark W. said:

It would be much easier to just use the Servo from a R/C airplane like one of the Cox foam R/C planes they have to be cheap used on eBay. Make a pulley to replace or glue to the servo arm then just string a rubber O ring or short TT belt of what ever over your volume knob.

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Mark, you are thinking exactly along the lines that I am. I have some RC airplane stuff that would do just fine, but needs some engineering refinement to allow that fine adjustment. The RC car thing is right up the available and cheap alley, just too fast in response. But I really appreciate the brainstorming and innovative approaches you guys come up with, even if some are in jest. Some of my best engineering innovations have come from crazier concepts.

Dave

Remote control

My next advancement will be this RF remote circuit (on the way). It is programmable for momentary contacts on the 2 relay outputs and it is only $18.95 shipped. I'm pretty sure I'll be able to fit the PCB inside of the current enclosure and the antenna will only need to be a short wire out of the rear (I only need about 20' of range). This would be a pretty neat system for a larger venue as the range is rated at 450' (YMMV).
JimB

Jim you have become the DIY switch master! Great work.

Rogers

roggom said:

Jim you have become the DIY switch master! Great work.
Rogers

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Well thanks! But actually I just don't have the patience for build-it projects that take over a weekend.
I save my patience for refurb and recapping projects. Next is my Sansui 3000.
JimB

Neat! :beer: +

Finished!!

I integrated an RF remote control unit today. It's a 2-button remote, 12 volt (wall wart) powered, with momentary contacts. The receiver has 2 - SPDT relays. I put a ground through both NC contacts and power to the NO contacts and connect each common (armature) to a motor (and LED) lead. The polarity swaps depending on which relay is activated. At rest both leads are at ground. I put a 6.2 volt zener diode in each line to drop the voltage to the motor to a safe level. The PCB also had a piezo "siren" that sounded when a signal was received; I removed that out of respect for the cat.
JimB

OUTSTANDING WORK!

:tresbon:

Every time I try the use the one I built it turns my neighbor's car alarm on!

N-i-c-e !!!