Ignition signal too low

Post Reply
CallensAlec
Posts: 8
Joined: 22 May 2017, 17:28
Your CAR: Toyota Yaris 1SZ-FE
SECU version: official SECU-3T
Has thanked: 5 times
Been thanked: 2 times

Ignition signal too low

Post by CallensAlec »

We're having issues with our ignition signal.

When nothing is connected to the IGN_OUTx output, we get a clean 5V ignition signal when starting. When connecting the igniter board to the IGN_OUTx output, the voltage drops to 1,93 V, but the signal remains, if measuring from the Coil x outputs on the igniter board going to our DIS coils, we only have about 0,40V left, but still with the signal in it. This is not enough to have a spark for us unfortunately.

Has somebody here already come across this problem or knows how to fix it? We are out of ideas at the moment.

Thanks in advance!
Attachments
Signal going to coils
Signal going to coils
Signal measured from IGN_INx on igniter board
Signal measured from IGN_INx on igniter board
Signal with nothing connected to IGN_OUTx
Signal with nothing connected to IGN_OUTx
User avatar
STC
Posts: 13843
Joined: 30 Apr 2013, 23:41
Your CAR: AZLK 2140
SECU version: DIY SECU-3
Location: North Korea
Has thanked: 2160 times
Been thanked: 4335 times
Contact:

Re: Ignition signal too low

Post by STC »

When connecting the igniter board to the IGN_OUTx output, the voltage drops to 1,93 V, but the signal remains,
It is normal, because BIP373 consumes some current into base-emitter. It is like a Darlington transistor. 1.92V is base to emitter voltage for BIP373.
bip373-saturation.png
bip373-saturation.png (7.92 KiB) Viewed 7936 times
if measuring from the Coil x outputs on the igniter board going to our DIS coils, we only have about 0,40V left, but still with the signal in it
I don't understand this. Please clarify measuring conditions.
Author of the SECU-3™ project http://SECU-3.org. An open source engine control unit / Ignition control system, (C) 2007.
Клуб проекта в Facebook https://www.facebook.com/groups/secu3club
Клуб проекта ВКонтакте https://vk.com/secu3club (вступаем!)
CallensAlec
Posts: 8
Joined: 22 May 2017, 17:28
Your CAR: Toyota Yaris 1SZ-FE
SECU version: official SECU-3T
Has thanked: 5 times
Been thanked: 2 times

Re: Ignition signal too low

Post by CallensAlec »

Thank you for this answer. We fixed the problem by using another transistor which allows more current to flow through it at the same voltage.

When we were measuring from the coil output on the igniter board, so the output going to the coils of the KMS DIS coil. That's where we got the 0,4 V signal.
Post Reply

Return to “SECU-3 (English)”