Maximum amperage draw of an engine ECU, please?

[Yhoni]

Hello friends, I am building an ECU power supply to connect by OBD to the ECUs on the table. The power supply has several positive outputs and several negative outputs, I also added a protection fuse.

I am missing a diode mount to protect the ECU from being mistakenly connected with reverse polarity.

Could someone tell me what is the maximum current consumption that a control unit could have to choose the right rectifier diode, please ?

Thank you.

[sebage]

Rectifier diode? Well, what kind of voltage source do you plan to use? If you plan to use a transformer, rectifier bridge and filter capacitor, you will also need to insert a voltage stabilizer (not necessarily to keep the voltage fixed, but to get rid of 50 Hz noise), or very large capacities for filtering.
If you do not connect anything to the ECU outputs (injectors, solenoid valves, induction coils ... etc.), the intensity of the absorbed current cannot be very high, regardless of the ECU. I would go for something of a 3-4 A, to ensure the charge of the capacitors from the internal sources of the ECU.

[Yhoni]

Rectifier diode? Well, what kind of voltage source do you plan to use? If you plan to use a transformer, rectifier bridge and filter capacitor, you will also need to insert a voltage stabilizer (not necessarily to keep the voltage fixed, but to get rid of 50 Hz noise), or very large capacities for filtering.
If you do not connect anything to the ECU outputs (injectors, solenoid valves, induction coils ... etc.), the intensity of the absorbed current cannot be very high, regardless of the ECU. I would go for something of a 3-4 A, to ensure the charge of the capacitors from the internal sources of the ECU.

Hello friend, my power supply is a UNI-T up to 30v and 6A stabilized.

At the moment I am going to use the assembly to diagnose the ECUs by obd but I would also like to be able to check the outputs of the coils, injectors, etc ...

Thank you.

[sebage]

So when you asked "Could someone tell me what is the maximum current consumption that a control unit could have to choose the right rectifier diode, please?" what diode did you refer to?
If you refer to the "antiparallel" protection diode, it is not related to the current absorbed by the ECU but must withstand higher current than is the protection fuse.
If you want to mount a diode in series with the ECU, I don't see where you could mount it, to be efficient, but in this case, you can safely choose a diode that can withstand the maximum current provided by your source, for example a 10A and 50V diode.


Offtopic: a bit difficult with the diagnosis of an ECU on the bench, because not having all the peripherals connected, you will have a lot of errors regarding the missing peripherals (sensors, actuators, injectors, ... etc.)

[Yhoni]

So when you asked "Could someone tell me what is the maximum current consumption that a control unit could have to choose the right rectifier diode, please?" what diode did you refer to?
If you refer to the "antiparallel" protection diode, it is not related to the current absorbed by the ECU but must withstand higher current than is the protection fuse.
If you want to mount a diode in series with the ECU, I don't see where you could mount it, to be efficient, but in this case, you can safely choose a diode that can withstand the maximum current provided by your source, for example a 10A and 50V diode.


Offtopic: a bit difficult with the diagnosis of an ECU on the bench, because not having all the peripherals connected, you will have a lot of errors regarding the missing peripherals (sensors, actuators, injectors, ... etc.)

You are right, the diode must withstand a higher current than the protection fuse to prevent it from blowing before the fuse.

The goal of installing a diode is to protect the circuit from a mistaken connection of the positive and negative terminals before the board built by me. I mean, between the Uni-T power supply and the breakout board that I built. This prevents the changed power from reaching the ECU and can damage it.

I have it in mind about the errors that the ecu will give when testing the components, but it will be in the future when I do the work if I have time. Now it is enough to be able to connect the ECU by OBD.

Thank you.

[Meat-Head]

Eh, as a rule would say 1.5/2 amps max, but there is a tractor ecu that draws 9 amps doing nothing

sorry in a rush try looking at playstaion xbox one if them psu 12v 30scamps

[drz]

Why don't you buy an atx power supply and not waste time? It has enough power, stable outputs (I use 12V and 5V), current protection and shortcut protection.

[Yhoni]

Hello friends, I finally ended up soldering a 1n4007 diode that supports -> 1000V RMS Reverse Voltage and 1A Average Rectified Output Curren so I understand that I am left over.

Is this correct and sufficient to protect against possible reverse polarity?

Thank you.

[Meat-Head]

If you connect ANYTHING reverse if not protected will go bang anyway

[Yhoni]

If you connect ANYTHING reverse if not protected will go bang anyway

Ok I get it but I mean the positive and negative feed from the ECU which is what I want to protect with the diode ....

Thank you.

[Meat-Head]

Ok send photos of what you mean, for example

you have a water butt full of water, in at the top, out at the bottom, your diode
’one way street’ don’t stop you putting your hose pipe up wrong hole on water butt

[Yhoni]

Ok send photos of what you mean, for example

you have a water butt full of water, in at the top, out at the bottom, your diode
’one way street’ don’t stop you putting your hose pipe up wrong hole on water butt

Ok friend, of course.

I attached a image.

Thank you.

[sebage]

Which method of protection do you want to adopt, after all?

Don't laugh at my artistic inclinations.

[Yhoni]

Which method of protection do you want to adopt, after all?

Don't laugh at my artistic inclinations.

Ok friend, your image is more curious than mine .

My chosen method is "B".

Is option "B" correct or is option "A" better?

Thank you.

[Meat-Head]

ON TOPIC:-

https://en.m.wikipedia.org/wiki/Crowbar_(circuit)

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tomtom 12volt to 5volt converters have or had this circuitry
idea is you get over voltage the thrysister goes deadshort quicker than a cannon ball or fuse

this saving your tomtom