Vibration For Minelab Equinox 600/800 For The Deaf

[greg801]

Hello, I am looking for a solution on how to vibrate the Equinox 600/800 detector for a deaf person who will use it underwater. As you know, a deaf person wears hearing aids that are not waterproof and cannot be immersed under water, and in these headphones he is not able to hear the signals, too much hearing loss is about 95dB.

I did a few attempts with a small amplifier and vibration motor from an old cell phone, but there are problems:

- after connecting the system to the Nox800 on the cable, the motor makes a slight buzzing noise but does not react to the metal signal in the coil,

- after connecting the system to the WM08 wireless module, the vibration works great on signals, but unfortunately after the detector is submerged under water, it loses the wireless connection.

- if I connect the headphone (computer) cable to the Noxa800 and at the end of the handset (the signal is heard in the headphones) I cut the cable and solder it to the system, vibration works great on the signals.

Why is it that the vibration does not work directly on the cable and it works through the headphone cable?
Is there anyone on the forum who will cover this topic?

One more thing. The deaf person uses an induction loop instead of headphones, which works with the hearing aid above the water and on the ground.
This loop connected to the detector via the cable is perfect, but when it is connected to the WM08, a buzzing can be heard in the background. How to do it to eliminate interference?

[PimentoUK]

Quote:"Why is it that the vibration does not work directly on the cable and it works through the headphone cable?"

I see the problem here. The Equinox uses electronic switching to determine if headphones are plugged in, then it mutes the internal loudspeaker and drived the headphones.
It measures the load placed on the Right channel, that is between the 'ring' and the 'ground' of the stereo plug. My experiments show 50 Ohms or less is needed to trigger the switch-over circuitry.
Probably the simplest method for you is to short the 'ring' to ground, and use the Left channel ( 'tip' ) to ground as your audio source.

I think the WM08 module would work underwater if it were placed very close to the control-box, so there was minimal water between them. The radio antenna in the control box is along the top edge, centrally positioned. The WM08 would probably need to be fitted into a watertight enclosure, I don't have one, so I'm unsure of it's water rating.

I can't help much with the loop / WM08 issue. The module has stereo output, is it possible to use both L and R to drive the loop, either by directly joining them, or with a pair of low-value resistors ( under 10 Ohms ? ) to isolate L and R.

Is the loop a low resistance ? Perhaps a series resistor may make it easier on the WM08.

[bklein]

“- if I connect the headphone (computer) cable to the Noxa800 and at the end of the handset (the signal is heard in the headphones) I cut the cable and solder it to the system, vibration works great on the signals.“

you lost me with this paragraph.  What computer cable? What handset? What system?

[GB_Amateur]

I typically try to help by going along with the proposal but in this case I'm making an exception.  Nokta Makro has for years been making detectors that vibrate, just to accomodate this situation.  It seems like you are needlessly trying to re-invent the wheel.

 

[PimentoUK]

He's not needlessly re-inventing the wheel ..... He's doing some fun engineering, extending the capabilities of his existing machine, with a budget that's probably under 10 US Dollars.

I admit that technically, it's far better to drive the vibe-motor with a specifically created signal direct from the microcomputer brains of a detector, than to take the audio signal, and make a vibe-driver. Audio signals are AC, vibe's need a DC drive. Audio covers a range of loudness that is wide on a linear scale, but our ears are fine with that ...  but vibe's have a much more restricted range for correct operation.

A fellow over on the Geotech1 forum had a go at doing this vibe add-on for one of his machines. Unfortunately his tech skills were rather lacking, but I believe his experiments did result in something that worked, so it's certainly worth some tinkering.

[GB_Amateur]

32 minutes ago, PimentoUK said:

He's not needlessly re-inventing the wheel ..... He's doing some fun engineering, extending the capabilities of his existing machine, with a budget that's probably under 10 US Dollars.

Fair enough.  I don't know enough about his situation (particularly priorities) and I happen to enjoy tinkering myself.  Greg, I wish you success in your efforts, and welcome to the forum!

[rvpopeye]

Greg 

Welcome aboard and interesting question.

I used to use subwoofers called Servo Drive that employed speakers with no voice coils and a motor with a linkage to the speaker cone that moved it physically instead of with magnetic fields like most other speakers  do .  The same old amplifiers were used to drive them too. Outperformed the regular subs by a large margin....

They would be a bit cumbersome for your application but they show a real world application of what you are attempting.  So , I think it could work .

Pimento seems to be on the right track , keep trying you'll get there.

 

[greg801]

On 10/11/2021 at 12:47 PM, PimentoUK said:

Quote:"Why is it that the vibration does not work directly on the cable and it works through the headphone cable?"

I see the problem here. The Equinox uses electronic switching to determine if headphones are plugged in, then it mutes the internal loudspeaker and drived the headphones.
It measures the load placed on the Right channel, that is between the 'ring' and the 'ground' of the stereo plug. My experiments show 50 Ohms or less is needed to trigger the switch-over circuitry.
Probably the simplest method for you is to short the 'ring' to ground, and use the Left channel ( 'tip' ) to ground as your audio source.

I think the WM08 module would work underwater if it were placed very close to the control-box, so there was minimal water between them. The radio antenna in the control box is along the top edge, centrally positioned. The WM08 would probably need to be fitted into a watertight enclosure, I don't have one, so I'm unsure of it's water rating.

I can't help much with the loop / WM08 issue. The module has stereo output, is it possible to use both L and R to drive the loop, either by directly joining them, or with a pair of low-value resistors ( under 10 Ohms ? ) to isolate L and R.

Is the loop a low resistance ? Perhaps a series resistor may make it easier on the WM08.

Thanks for the tip.

I found something like this: https://youtu.be/iShD8pGeYR8?t=136

[greg801]

On 10/11/2021 at 4:35 PM, bklein said:

“- if I connect the headphone (computer) cable to the Noxa800 and at the end of the handset (the signal is heard in the headphones) I cut the cable and solder it to the system, vibration works great on the signals.“

you lost me with this paragraph.  What computer cable? What handset? What system?

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