EGT Conditioner

[Ivaylo Angelov]

Hi all,

Just bought a 2ch EGT-K amplifier from Reveltronics.com: https://www.reveltronics.com/en/products/egt-k-thermocouple-amplifier-type-k-0-5v

What bothers me is the fact (according to the insructions) that the OUT GND is internally connected to the device power GND i.e. to the chassis GND.

So , the EGT-K OUT1 and OUT2 are connected to two of my G4 AN Volt input channels. So far, so good but what G4 GND should I wire  to the EGT-K OUT GND? If I wire  the G4's  sensor GND, I'll actually conect that sensor GND to the chassis via the EGT-K device? Is that OK for the G4's all other sensors and measurement?

Endless thanks in advance!

Regards!

 

[Greg W]

I expect it will be a power or chassis ground because of the 12v input not a 5 v input 

[Adamw]

6 hours ago, Ivaylo Angelov said:

What bothers me is the fact (according to the insructions) that the OUT GND is internally connected to the device power GND i.e. to the chassis GND.

Have you got a link for the instructions?  I only found a datasheet but didnt see that comment on there.  Im interested to know the quoted power consumption as if it is relatively low (say <100mA) you could then connect it to sensor ground.

[neil brown]

Interested as was looking at same set up for a single egt to fit

[Ivaylo Angelov]

Hi to all,

Unfortunately it seems I have left my EGT-K wiring instructions in my garage, which is located not where I live. Next few days I'll try to pass by and collect the wiring and then to scan/picture it. But it is not something special. I don't see any quoted power consumption, but will ask. 

BTW I connected the guys from Reveltronics with the same question. Here is their responce:

"OUT ground is internally connected to EGT power supply ground. You can 
left it foating for not grounded thermocouple (thermocouple for vehicles 
are usually not grounded).
All vehicle sensors have ground from vehicle ground.
EGT-K power supply ground is also vehicle ground, so both grounds are 
connected via vehicle ground.
Just connect only OUTx to your ECU AdcX input."

To me, It looks not so correct for my case at least where all sensors have "Sensor GND" from the G4 ECU, not from the vehicle GND. What do you think?

Thanks again!

P.S. Also invited them to join the forum and comment into this thread.

[Adamw]

8 hours ago, Ivaylo Angelov said:

To me, It looks not so correct for my case at least where all sensors have "Sensor GND" from the G4 ECU, not from the vehicle GND. What do you think?

I agree, it would always be better to have a sensor reference the ECU sensor ground, not chassis ground.  You will often find the measurement will change when you turn on the headlights or fan when connected via chassis ground.  If they confirm the average power consumption is low then just connect the main device ground to ecu sensor ground will solve the problem.

[RVL]

Hi Guys,

EGT-K 2CH power consumption is ~2-3mA @ 12V.
OUT ground is internally connected with IN ground.
Sensors ground in your ECU is chassis ground with separate filtering for analog circuit - right?

You can connect it in two ways:

Using vehicle ground (chassis ground):
- EGT-K OUT signal to Adc input in ECU
- EGT-K OUT ground left floating
- EGT-K VCC input to +IGNITION or +BAT
- EGT-K GND input to -BAT or chassis ground.

Using ecu sensor ground:
- EGT-K OUT signal to Adc input in ECU
- EGT-K OUT ground to ECU sensor ground
- EGT-K VCC input to +IGNITION or +BAT
- EGT-K GND input left floating

Both cases will work. Second case will be more immune for external noise on ECU's power line.

Hope it helps.

[Ivaylo Angelov]

A happy chap here!

As was promissed, here are the Reveltronics wiring instructions:

Then I wired the EGT-K OUTs to G4's AN V10 and AN V11. I left the input GND floating and connected  the G4 sensor GND only to the EGT-K OUT GNDs.

Everything is OK now! I have EGT live data. Since  I'm on budget, I used China made EGTs, it appeared the + is RED and  -  is BLK.

Thanks again to Link's and Reveltronics support! You were just great!