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Wireless remote contolled volume control for stereo unit.

PostPosted: Mon Jun 26, 2017 2:46 am
by Robbo
For some time now, I have been bugged by having to get up and attend the stereo unit to adjust the volume or mute it. All of my entertainment devices are channelled through the stereo unit. The TV, PVR/CD/DVD and streaming video services etc. are no problem as I can use the appropriate remote controls. It's when I am using the 'dual auto reversing cassette player', FM radio or turntable that I need a remote control. Going through my many boxes of components and recovered items from various defunct bits of equipment, I came accross a hi-torque 12 volt DC motor that had a worm gear driving a cam to operate a limit switch and another cam to throw a dead locking bolt for an experimental door dead lock. The cam drive was too fast for the use I intended it for and soon found running it on 2.5 volts DC was just right and still with sufficient torque to drive a dual potentiometer. The cams were not suitable, as they were set to operate at 90 degrees. Removing them, cutting down and filing, soon overcame the issue to operate at 170 degrees and adding another limit switch, fixed the issue. Next I had to modify the stereo unit by cutting the printed circuit tracks connecting the unit's dual volume control potentiometer and wiring them to a 'change-over' relay so that when the relay is in its quiescent state the stereo unit's volume control is in circuit. When energised, the relay switches the stereo unit's VC OUT of circuit and the external remote volume control IN.
A red LED shows when the remote unit is in control, a yellow LED indicates when volume is being increased and a green LED when volume is being decreased.

Trusting that some of you model enthusiasts will find interesting.

http://media.fotki.com/1_p,rtfkdfskqwwg ... Cam-vi.jpg
The 170 degree cam and hi volume limit switch.

http://media.fotki.com/1_p,rtfkdfskwksw ... Cam-vi.jpg

The low volume cam & limit switch.

http://media.fotki.com/1_p,rtfkdfsksrkb ... irc-vi.jpg

The completed wired motor and reversing relay assembly with the 12v to 2.5v motor regulator circuit board.

http://media.fotki.com/1_p,rtfkdfskdssk ... bly-vi.jpg

The completed assembly with the motor, dual potentiometer, 2.5v regulator board and 315mHz remote control wireless receiver.

http://media.fotki.com/1_p,rtfkdfskdgbf ... rol-vi.jpg

The compact 4 CH remote control transmitter.

http://media.fotki.com/1_p,rtfbwtgktgwr ... it_-vi.jpg

The change-over relay in the stereo unit.

http://media.fotki.com/1_p,rtfkdfrqskrr ... nit-vi.jpg

The completed unit sits on the stereo unit. The red LED was too bright, hence the tape strip. Will modify the circuit later.

Re: Wireless remote contolled volume control for stereo unit

PostPosted: Thu Jun 29, 2017 9:43 am
by chariots of fire
As they used to say back in the '70's........."Far out,man...Far out! :idea: ;)