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Topic: Newbie project advice please!! (Read 133 times) previous topic - next topic

mack85n

Hi,

I'm new to ardinuo and would really appreciate some help if this project is possible. I'm trying to construct a unit for controlling a Lock Up solenoid on a transmission that uses a factory 5V output at present.
It would need to be able to have 3 inputs that could be used to enable a 5V output eg. Input 1,2 active and 3 inactive would allow the 5V output to switch. But if these conditions are not met the system would not activate the 5V output.
It would also require a step down from a 12V input.

Sorry if this is a rookie question but I've only just found arduino and think it may have amazing possibilities for myself.

TIA

Paul_KD7HB

You need to measure the current used by the 5 volt solenoid.

Paul

mack85n

Hi,

It operates on a PWM circuit at 1 Amp from what I have read.

Jonarotz

Hi,

It operates on a PWM circuit at 1 Amp from what I have read.

Is this for a transmission swap into a different vehicle? From my experience there is a strategy to the PWM lockups. It will start at roughly a 50% duty cycle and increase to 100% (full lockup). You may want to look into that strategy to avoid burning it up.

The Arduino has a 5V output which should work, but I don't think it is going to handle the amp draw of the solenoid.

I am assuming your 3 inputs are going to be throttle position, manifold pressure, rpm, maybe even vehicle speed?

My advice would be to separate each of those inputs and get one to work at a time then add them one at a time. Use an LED to simulate the lockup solenoid this way you can observe the behavior.

I don't have a strong code background, I am new to this myself. I do however have a strong automotive background so I can help you on that end.
 

mack85n

Is this for a transmission swap into a different vehicle? From my experience there is a strategy to the PWM lockups. It will start at roughly a 50% duty cycle and increase to 100% (full lockup). You may want to look into that strategy to avoid burning it up.

The Arduino has a 5V output which should work, but I don't think it is going to handle the amp draw of the solenoid.

I am assuming your 3 inputs are going to be throttle position, manifold pressure, rpm, maybe even vehicle speed?

My advice would be to separate each of those inputs and get one to work at a time then add them one at a time. Use an LED to simulate the lockup solenoid this way you can observe the behavior.

I don't have a strong code background, I am new to this myself. I do however have a strong automotive background so I can help you on that end.
 
Jonarotz you are spot on! It does modulate in the exact way you describe. To avoid the harsh Lock-up engagement it starts at a lower application and increase over a short amount of time. I tested the current draw and it is maximum of 600 mA. Is this too much for an Arduino?

Whilst the factory TCU uses the inputs of TPS and Road Speed I only want to supplement the OEM system with a manual lock up activation.

On the face of it I could control it with an aftermarket ECU GP PWM output, but id like to develop a standalone controller for it.

It's  not for a trans swap, just a mod to allow a liitle more control over the Lock up. The Inputs are:
Switched - via momentary (operator controlled)
Switched - P/N/D - to be activated when in gear - TCU signal grounds under these conditions

And also it must be able to be bypassed by the OEM system, I created a relay switched unit but it throws an open circuit fault when manually activated as the TCU picks up an O/L on the commanded circuit.

Any help would be great!

eddyman

This is a toughie cause of a number of variables, some have already touched on it and with limited knowledge of transmission type, and vehicle it would be difficult to give specifics. Torgue speed is a major factor is lockup which runs off speed sensor. you could possibly lower the threshold for min input and remain in lockup, however internal damage to the torque may result. The TCU will be calibrated depending on unit hrsp and torque settings. If you can moniter accel pedal, speed sensor, manifold, and possibly each shift solenoid will give you the shift pattern range to help with possible PWM input thresold.

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