DC-DC Converter

[timjet]

I got this DC-DC converter: http://cgi.ebay.com/ws/eBayISAPI.dl...1067121915&view=all&tid=1237436412015&guest=1

The purpose was to protect my electronic equipment from turning off when I start the engines.

I connected it to my plotter, gps sensor, heading sensor and depth gauge. I have raymarine equipment which has the seatalk communication protocol. I also connected this to the converter, but have no idea of the power consumption of the seatalk system. The total amp draw from all this equipment except seatalk was less than 6 amps. When I connected it, the plotter could not obtain a fix and the depth gauge did not work. The plotter worked fine. I did not try starting the engines.

Could it be possible that the seatalk system draws so much power that the converter can't keep up. Again I never did start the engine so the converter really never was tested but it basically didn't supply enough power to power the gps and depth gauge which together draw less than half an amp.

Any ideas?

 

[captrigney]

You must have bought the last one. The link is empty. Can you post the brand and model of your converter? How did you connect it?

I'll be doing the Trent Severn canal this summer and they require shutdown in the locks. My electronics shut down on startup too.

Are there any other solutions out there?

 

[timjet]

I just checked the link and it worked fine for me.

8V-40V to 12V 6A Max 72W DC-DC Step Down Converter Voltage Transformer F Vehicle



An alternative to the converter is to connect electronic equipment to a battery that is not used to start the engines. I can't isolate my batteries, however I can connect my electronic equipment to my generator start battery which is only used when I anchor and the electronics are shut off.
Problem with this is the gen start battery does not get charged by the engine alternators, only by the AC battery charger. If I connected the electronics to my gen start battery I would have to monitor it more carefully.

It's not good for the electronics to shut down due to low voltage during engine start.

 

[HopCar]

Newmar makes a product called StartGuard that is designed to do just what you're trying to do. Newmar makes very good products. I have a Newmar battery charger that is great.
Here is a link to their website; DC Power Onboard with Newmar’s DC Power Conditioners. Newmar’s power array of dc conditioners provide stabilizing voltage during engine crank, voltage stabilizers with Isolated DC-DC converters, electronic noise filters and automatic powe

 

[timjet]

Thanks HopCar.
At $154 a bit more than the $30 I paid for the one that didn't work. For good reason!

 

[Brooksie]

timjet, I couldn't get the link to work either but:
I bought a DC-DC converter on ebay to protect my LED lights so I think I know what you have and I think you will have the same problem I had. When the voltage is above 12, like when charging it had no problem regulating the output to 12 thus protecting the LED's but when the voltage goes below 12 (as when starting), it can't boost it to 12 so electronics will drop out. No prob for LED's tho.

The Blue Seas ACR-SI has the feature you are looking for and more for $65 or $80 depending on capaicity.