Ontopic A Thread About Butt Mustard, For Those Who Drive Automobiles

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@gee
I think I need a kind of secondary horn. I still want to be able to give a friendly little beep-beep, but if I hold down the horn button for more than X time and it activates the angry horn.

There anything readily available for that? If not, what sort of circuit do I need?
Just wire up a second button or switch to this horn:
 
I can appreciate having different horns to use. Have long thought about hooking up one that sounds like a semi tractor or freight train locomotive. But I also think it's best incorporated having its own button.
I think having a single "hold it longer for more horn" function would be more frustrating/impractical than separate buttons.

It would be cool to have the second horn button on the steering wheel.

Could figure out adding one. Or if yours is new enough could repurpose one of the many steering wheel ones you don't really need, like one that changes radio stations or climate control temp.
Or add one to the shift lever. Or a floor button like an old school dimmer switch.
 
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Damn, I can only think of the ghetto way (relabel the axis on the gauge).

Good luck, maybe @gee will have more insight. :/
I'm gonna need to do something other than ghetto anyways as the gauge with the sender only barely reads at WOT, Max RPM (plug the values in for amperage at 12V and I think 40PSI kind of matches 5-10 PSI)

Playing around, maybe a 30ohm resistor in parallel gives halfway decent numbers, but you over balance on one end or the other of the gauge
 
So, I've measured the sender and the gauge. What do I need to do to get these to talk properly?
Gauge position is roughly approximate.
View attachment 6870
Having trouble reading this table...

- You've got an oil pressure sender on the block, and the "sender" table is a resistance measurement,
- Gauge reads the PSI value in the leftmost column when it sees the resistance (?) in the right column?
 
Having trouble reading this table...

- You've got an oil pressure sender on the block, and the "sender" table is a resistance measurement,
- Gauge reads the PSI value in the leftmost column when it sees the resistance (?) in the right column?
Sender is measured resistance values (air pressure and a multimeter.)
Gauge is approximate position of the oil pressure needle based on sending 12V through a decade box and adjusting ohm values on the box (see image below.) Ohm value is recorded in the table

I need to match the sender to the gauge.

20190409_125634.jpg
 
Do you have a variable bench supply?

If so, put a DMM set to current measurement in series with the power supply, and make a measurement of current vs gauge angle.
Also, measure the DC resistance of the gauge.

It'll make this a bit easier to figure out.
 
Don't worry about the series resistor.

power supply positive <-> DMM current measurement input
DMM common <-> gauge positive
power supply negative <-> gauge negative.

Turn power supply down to 0V, turn it on, then turn up the voltage and the gauge should turn up/down with the voltage, and the current should change proportionally with the voltage.
 
Don't worry about the series resistor.

power supply positive <-> DMM current measurement input
DMM common <-> gauge positive
power supply negative <-> gauge negative.

Turn power supply down to 0V, turn it on, then turn up the voltage and the gauge should turn up/down with the voltage, and the current should change proportionally with the voltage.
0.05V, 0.01A and its at max, but its slow to respond. Up the amperage and it slams into max.

Voltage normally comes straight from the battery, so it's at least 12V.
 
Measure the resistance of the coil on the meter. Also, 0.01A isn't all that precise - does your meter have a lower range mA setting you can use that's more precise?

Basically what I'm doing is trying to figure out how much current through the meter (and voltage across the meter, based on its resistance) gives a certain reading, that I can throw in a table next to your sensor resistance readings.

Then I can toy around with things like adding resistors to see if I can make something that works adequately, or if I'm gonna have to propose building something with a breadboarded Arduino or similar to make it work.
 
I've got like a thousand dollars' worth of polyurethane bushings to install in the Audi, and it needs them, kinda badly. It makes some lovely knocking sounds going full lock over bumps.

Basically everything available here in "street hardness", plus a couple extras from a forum guy who knows some tricks to make a more reliable FLCA bushing.

I'll probably buy a couple dozen zerks and drill the bushings so I can regrease them when they need it.
 
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I've got like a thousand dollars' worth of polyurethane bushings to install in the Audi, and it needs them, kinda badly. It makes some lovely knocking sounds going full lock over bumps.

Basically everything available here in "street hardness", plus a couple extras from a forum guy who knows some tricks to make a more reliable FLCA bushing.

I'll probably buy a couple dozen zerks and drill the bushings so I can regrease them when they need it.

So some things haven't changed from the 80s huh.
 
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