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PICO system for characterising ignition system performance
PICO system for characterising ignition system performance
Hello all,
I have a customer who needs to characterise the performance of the ignition system on a top fuel drag bike.
I am hoping to identify the Pico scope he would need, as well as the necessary accessories, to do the job.
I've attached a drawing he has provided which shows the four points of measurement he requires: voltage at point 1 and points at 3 (there are two points there), and current at point 2. Note that the peak voltage at point 1 should be somewhere in the 50-60kV range, so I assume we will need a big divider on that channel.
I think he needs to be logging these four channels simultaneously to understand what the system is doing, and at a sampling rate high enough to capture the signal detail.
Can someone please point me in the right direction of a suitable DAQ unit to start with?
Any advice around the voltage divider lead would be hugely appreciated too.
Kind regards and thanks in advance,
Cal
I have a customer who needs to characterise the performance of the ignition system on a top fuel drag bike.
I am hoping to identify the Pico scope he would need, as well as the necessary accessories, to do the job.
I've attached a drawing he has provided which shows the four points of measurement he requires: voltage at point 1 and points at 3 (there are two points there), and current at point 2. Note that the peak voltage at point 1 should be somewhere in the 50-60kV range, so I assume we will need a big divider on that channel.
I think he needs to be logging these four channels simultaneously to understand what the system is doing, and at a sampling rate high enough to capture the signal detail.
Can someone please point me in the right direction of a suitable DAQ unit to start with?
Any advice around the voltage divider lead would be hugely appreciated too.
Kind regards and thanks in advance,
Cal
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Steve Smith
- Pico Staff Member
- Posts: 1591
- Joined: Sun Aug 25, 2013 7:22 am
Re: PICO system for characterising ignition system performance
Hello Cal and thank you for the post
Most certainly the PicoScope 4425A will capture the four channels of data you require. The links below will point you to the scope and the specifications which will cover you for high speed ignition events.
https://www.picoauto.com/products/autom ... s-hardware
https://www.picoauto.com/products/autom ... ifications
Could you confirm the likely maximum engine speed you will encounter?
Thank you for the drawing too as this does help, however I have a question about measuring HT current.
Forgive any misinterpretation but you have indicated from the drawing at measurement point 2 you may wish to measure current (0.4-0.8 amps) and 40-50 kV (up to 2 Amps) at point 1; Wow that is a lot of energy!
We can measure the voltage using our HT Pick Up leads here and this will also do for measurement 2 too, please see the link below:
https://www.picoauto.com/products/ignit ... ion-pickup
These leads are 1.8 meter in length and will measure up to 100 kV in conjunction with our PicoScope 7 software which you can download and run in demo mode for free here https://oem.picoauto.com/p7beta/download
You can see example waveforms of our secondary ignition captures in the Guided Tests that are presented to you when you open PicoScope 7. Click on Ignition>Distributor and chose our desired secondary ignition set up
Regarding current measurements at point 1 and 2, whilst we have experimented here, the relevant attenuated HT Pick up leads (listed above) provide the necessary profiles of ignition with the relevant bandwidth and shielding for such high frequency/energy signals
Measurement point 3 looks to be a pulsed signal from the distributor to the Ignition box (Engine speed/position signal)
I am assuming this is all low tension and in no way linked to the ignition coil primary circuit?
If so, you will need the relevant x 1 BNC+ test lead (TA404) and associated signal probe & croc clip for your ground reference. These can be found here: https://www.picoauto.com/products/accessories
If the signal at point 3 is linked to the coil primary circuit, then you will require an attenuated test lead as the voltages here can exceed 500 V. In this scenario you will need a scope probe https://www.picoauto.com/products/test- ... be-adaptor
One final question Cal, how long would you be measuring for as I would be conscious of heat soak/absorption via the test leads and scope etc. during Dyno testing for example?
I hope this helps, take care……Steve
Most certainly the PicoScope 4425A will capture the four channels of data you require. The links below will point you to the scope and the specifications which will cover you for high speed ignition events.
https://www.picoauto.com/products/autom ... s-hardware
https://www.picoauto.com/products/autom ... ifications
Could you confirm the likely maximum engine speed you will encounter?
Thank you for the drawing too as this does help, however I have a question about measuring HT current.
Forgive any misinterpretation but you have indicated from the drawing at measurement point 2 you may wish to measure current (0.4-0.8 amps) and 40-50 kV (up to 2 Amps) at point 1; Wow that is a lot of energy!
We can measure the voltage using our HT Pick Up leads here and this will also do for measurement 2 too, please see the link below:
https://www.picoauto.com/products/ignit ... ion-pickup
These leads are 1.8 meter in length and will measure up to 100 kV in conjunction with our PicoScope 7 software which you can download and run in demo mode for free here https://oem.picoauto.com/p7beta/download
You can see example waveforms of our secondary ignition captures in the Guided Tests that are presented to you when you open PicoScope 7. Click on Ignition>Distributor and chose our desired secondary ignition set up
Regarding current measurements at point 1 and 2, whilst we have experimented here, the relevant attenuated HT Pick up leads (listed above) provide the necessary profiles of ignition with the relevant bandwidth and shielding for such high frequency/energy signals
Measurement point 3 looks to be a pulsed signal from the distributor to the Ignition box (Engine speed/position signal)
I am assuming this is all low tension and in no way linked to the ignition coil primary circuit?
If so, you will need the relevant x 1 BNC+ test lead (TA404) and associated signal probe & croc clip for your ground reference. These can be found here: https://www.picoauto.com/products/accessories
If the signal at point 3 is linked to the coil primary circuit, then you will require an attenuated test lead as the voltages here can exceed 500 V. In this scenario you will need a scope probe https://www.picoauto.com/products/test- ... be-adaptor
One final question Cal, how long would you be measuring for as I would be conscious of heat soak/absorption via the test leads and scope etc. during Dyno testing for example?
I hope this helps, take care……Steve
Re: PICO system for characterising ignition system performance
Hi Steve,
Thank you very much for the quick reply, and sorry for the delay on mine!
I will ask the questions regarding max RPM and the signal at measurement point 3 and get back to you.
There may be an error there in the measurement of 'up to 2A' at point 1 - yes, 100kW is a lot of energy!
Yes I understand he hopes to log this data during a dyno session. I will make sure he keeps the heat soak in mind!
Thanks again!
Cal
Thank you very much for the quick reply, and sorry for the delay on mine!
I will ask the questions regarding max RPM and the signal at measurement point 3 and get back to you.
There may be an error there in the measurement of 'up to 2A' at point 1 - yes, 100kW is a lot of energy!
Yes I understand he hopes to log this data during a dyno session. I will make sure he keeps the heat soak in mind!
Thanks again!
Cal