Power Spikes

[Soeley]

Does anyone know anything about Power Spikes? (Not sure I’m even using the correct terminology).

I have been having a problem with my BlackVue Dash-Cam http://www.blackvue..../sub1.asp?idx=7; it keeps shutting down and restarting on its own. It didn’t used to do it but started and got worse and worse over last month or so. I have sent it back to the seller who is testing it on the bench and has had no problem with it yet; it is he who has said he has heard Power Spike can cause problems.

The camera is wired through a PowerMagic Pro http://www.blackvue....sub1.asp?idx=13 which allows the camera to operate on parking mode with the ignition switched off, but will not allow the Battery to drain.

Any way I have only sent the camera back on its own, so today I propped my digital multi-meter on the dashboard and connected it to the power lead for the camera. At first I was getting a steady 14.2 volts with the engine running and driving around. After about half an hour or so the voltage went up to 14.8 and dropped to 12.5 then back up to 14.8 again and a few readings in between.

Is this a Power Spike, or would you expect to see a bigger fluctuation in voltage?

I am going to try the same thing tomorrow but without the PowerMagic Pro, with the power lead plugged straight into the cigar socket and see what sort of reading I get then.

Is there a way to filter/regulate foe a steady voltage?

Any suggestions would be appreciated.

[tarquin]

I think your measurements are red herrings. A"spike" would be so fast you would probably not see it on a digital meter. The voltage fluctuation you are seeing is the intelligent charger the iQ has. Will have a think about your problem

David

[tarquin]

One thing springs to mind. Try another memory card. Sometimes the TOC table of contents corruption can cause devices to re- boot

David

[Soeley]

Thanks for putting your mind to it David, I have two memory cards the 16GB (class 6) it came with and I bought a Sandisk 32GB (class10) to use in it. I get the same problem with both cards, they get fully formatted weekly as recommended by manufacturer, I have also checked them out on the laptop for any bad sectors. I even re-downloaded the firmware and re-installed that to the camera, but no joy.

[tarquin]

Mmm you have been pretty thorough. Will think some more

David

[tarquin]

Does it shut down and re-start. Whilst driving or only when parked ignition off or both

David

[Soeley]

Have not noticed a pattern, It can do it any time, parked up, driving at any time.

I went for the same drive today (about 50 miles) with the power lead plugged in to the cigar lighter and NOT the PowerMagic Pro. I got a much more steady voltage reading, stayed at more or less 14.2v. Is the cigar lighter socket run through a filter/regulator?

[tarquin]

Certainly the socket is run from a control function with-in the ECU or sub assembly. As to whether its regulated or not i havent noticed. 14.2 is a bit high mine is nominal at 12.7. Will check and give you my findings in a couple of days

David

[tonyishuk]

Voltages seem Ok, I had a dash board camera which was powered via a usb cable and 12V charger. Not sure how yours is connected but the arrangement suffered from cables moving in the sockets however I tried to secure them (Velcro to araldite).(Or dry joints in the`circuits ?)

In the end I purchased a Roadhawk dash cam which has a buffered input, no problems since !

Rgds

14.2 Volts or so would indicate to me a starting charge for a Battery or a Battery that might be low in capacity due to insufficent charging whilst on shortish runs. Volts will drop to about 13 to 13.5 on normal running.

[Soeley]

Ok, it is deffinately runnining it straight from the Battery that is the issue. I sent the camera back and they tested it and found no problem with it. Upon recieving it back I plugged the power lead into the cigar lighter and it has totally behaved since. The only problem with this is the camera switched off with the ignition.

S|o to overcome the problem I need to fit a regulator/stabilizer between my power feed (battery) and PowerMagic Pro. I have seen these but know nothing about them:

http://www.ebay.co.uk/itm/DC-DC-LM2596-Converter-Buck-Adjustable-Step-Down-Regulator-Power-Module-1-2-35V-/370624565910?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item564af21296

http://www.ebay.co.uk/itm/DC-DC-Converter-Regulator-8V-40V-Step-Down-12V-3A-36W-Voltage-Stabilizer-/300693940163?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item4602c167c3

Just wondering if car audio shops sell something similar?

[tarquin]

The problem is any regulator or DC-DC inverter will have a constant drain on your Battery. Flattening it if left. I know the IC used in the DC-DC converter and i would say its quite fast acting but if you think its a form of voltage spike i don't think it will suppress it. First i would try a 100uf 25v capacitor across the output of your power monitor and camera. This would do a fair job of line regulation. Available from Maplin

David

[Soeley]

David, not exactly sure what you mean? So I've done a (poor) Photoshop to illustrate my understanding.

The way the PowerMagic Pro is wired is as follows:

Orange wire - Ignition Live

Yellow wire - Permanent Live

Black - Earth

My understanding of the way it works is this. The unit takes the power from the permanent live all the time, the ignition live is so the the unit can detect when the ignition is switched off so that it can allow the Parking Mode to be automatically switched over from Normal recording. One of the benefits of the PowerMagic Pro is to prevent any re-booting of the camera during engine starting, ignition being turned on and off.

So, is this what you meant with the Capacitor?