Re: [EVDL] DC-DC Cooling
On Wed, Oct 8, 2014 at 12:53 AM, John Lussmyer via EV ev@lists.evdl.org wrote: On Tue Oct 07 21:33:02 PDT 2014 j...@ecoreality.org said: I agree with others that the parallel Vicor modules may be fighting with each other. Are they adjustable? If so, you could sum them via a Schottky isolator, but it will drop about 0.2 volt, which you'd probably want to adjust out. Already doing that. Actually, I'm seeing a bigger voltage drop across the 30A fuse on each module than I am across the diodes. This electronical stuff is outside my comfort zone, but I thought one of the reasons for using Vicor modules is that they are made to play nicely. One driver, X slaves, the driver runs the show and everyone shares. Assuming no external issues like that hot fuse, of course. Chris -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141008/77764988/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
John; Not sure what pack size you have, but Evolve sells a Zivan, 100-200V - 50A DC/DC. I've had a Zivan for 4.5 years with no issues, but I have to admit, I'm not pulling the current you are. Thanks; Dennis Elsberry, MO http://www.evalbum.com/1366 http://evalbum.com/3715 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of John Lussmyer via EV Sent: Tuesday, October 07, 2014 11:03 PM To: Electric Vehicle Discussion List; Jan Steinman Subject: Re: [EVDL] DC-DC Cooling On Tue Oct 07 19:05:39 PDT 2014 ev@lists.evdl.org said: From: John Lussmyer via EV ev@lists.evdl.org ... when I'm running 40A continuous load... Wow, what the heck are you running? That seems like a very high load, even with lights on. Are you using 12V resistance heating? No Note this is a F250 truck. So, just sitting with the ignition on runs: Cooling blower for motors, Power steering pump, along with the usual 12v draw of the truck. Then I add Headlights, Heater Blower, Windshield Wipers, Stereo. There is also the occaisional 40A draw from the Brake Vacuum Pump. Not much load to shed. -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
From: John Lussmyer via EV ev@lists.evdl.org ... when I'm running 40A continuous load... Wow, what the heck are you running? That seems like a very high load, even with lights on. Are you using 12V resistance heating? Perhaps you would be better off looking at load shedding than providing more cooling to your DC converter? Our food system is cruel to animals, damaging to other wildlife and destructive of the soil. It has also caused great harm and suffering to farmers. The suicide rate among farmers is three times that of the country as a whole. People who love their farms, care about the farm animals and protect the soil for future generations have been replaced with large agribusiness farms and Contained Animal Feeding Operations (CAFO). The loss of the personal touch of the dedicated farmer at the expense of fossil fuel based methods of growing crops and animals has increased yields while damaging land, waterways and lives... The average US farm worker has a life expectancy of just 49 years. -- Pat Murphy Jan Steinman, EcoReality Co-op ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
On Tue Oct 07 19:05:39 PDT 2014 ev@lists.evdl.org said: From: John Lussmyer via EV ev@lists.evdl.org ... when I'm running 40A continuous load... Wow, what the heck are you running? That seems like a very high load, even with lights on. Are you using 12V resistance heating? No Note this is a F250 truck. So, just sitting with the ignition on runs: Cooling blower for motors, Power steering pump, along with the usual 12v draw of the truck. Then I add Headlights, Heater Blower, Windshield Wipers, Stereo. There is also the occaisional 40A draw from the Brake Vacuum Pump. Not much load to shed. -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
Wow. I had no idea. Don't suppose you could run your brakes and steering from mechanical pumps coupled to your drive motor? That would be more efficient, and save you a bit of range. That's what I plan to do in the conversion I'm working on. I agree with others that the parallel Vicor modules may be fighting with each other. Are they adjustable? If so, you could sum them via a Schottky isolator, but it will drop about 0.2 volt, which you'd probably want to adjust out. If you can't find Schottky isolators, you could sum the outputs via small resistors. 5 milliohms would drop only 0.2 volts at 40 amps, and would balance the load on the modules. Or you may want to can the parallel module concept, and use a single converter rated for the amperage you need. That's the most expensive option, but the other options all require more effort. Jan On 2014-10-07, at 21:02, John Lussmyer wrote: On Tue Oct 07 19:05:39 PDT 2014 ev@lists.evdl.org said: From: John Lussmyer via EV ev@lists.evdl.org ... when I'm running 40A continuous load... Wow, what the heck are you running? That seems like a very high load, even with lights on. Are you using 12V resistance heating? No Note this is a F250 truck. So, just sitting with the ignition on runs: Cooling blower for motors, Power steering pump, along with the usual 12v draw of the truck. Then I add Headlights, Heater Blower, Windshield Wipers, Stereo. There is also the occaisional 40A draw from the Brake Vacuum Pump. Not much load to shed. -- Tigers prowl and Dragons soar in my dreams... Risk Assessment in the hands of centralized corruptible agencies is no protection for consumers as the disease and health epidemic in the U.S. linked to over processed, industrial foods shows. Even while the U.S. is at the epicenter of the food related public health crises, the U.S. government is trying to export its Food laws which deregulate the industry and over regulate ordinary citizens and small enterprise. This deregulation of the big and toxic and over regulation of the small and ecological is at the core of Food Fascism... -- Vandana Shiva Jan Steinman, EcoReality Co-op ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
[EVDL] DC-DC Cooling
On Mon Oct 06 16:21:01 PDT 2014 ev@lists.evdl.org said: I think I'm going to have to figure out how to water cool my DC-DC. I built this one using 4 Vicor 20A bricks to get a 80A capable unit. It all fits on the back of a 6 square 2 thick heatsink with a 6 fan on it. I'm noticing that when I'm running 40A continuous load, the output starts becoming erratic. Ther fan on the heatsink doesn't seem to be enough when I'm drawing a lot of 12V power. (blower, lights, brakes, etc..) I found at least part of the problem. The bolt on the common 12v ground had come loose. this meant that EVERYTHING had a flakey ground connection, as that is where the battery, accessories, dc-dc, are all tied together. I've also found a bad connection on my 12V Ammeter, so that is part of the reason it was jumping around. Still need to do more testing, as I was noticing that the voltage drop across the fuse on 1 of the 4 Vicor bricks was MUCH higher than the others. (like .5V vs .1v) Fuse didn't blow though. -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
On 10/7/14, 9:02 PM, John Lussmyer via EV wrote: On Tue Oct 07 19:05:39 PDT 2014 ev@lists.evdl.org said: From: John Lussmyer via EV ev@lists.evdl.org ... when I'm running 40A continuous load... Wow, what the heck are you running? That seems like a very high load, even with lights on. Are you using 12V resistance heating? No Note this is a F250 truck. So, just sitting with the ignition on runs: Cooling blower for motors, Power steering pump, along with the usual 12v draw of the truck. Then I add Headlights, Heater Blower, Windshield Wipers, Stereo. There is also the occaisional 40A draw from the Brake Vacuum Pump. Not much load to shed. Ah, I think you pointed out the issue: the brake vacuum pump. Here is what I suggest: get a hand-held IR temperature measurement device, and then while everything is running (include the vacuum pump) check for heat on the modules. Also, measure the total current when everything is running. I looked at a lot of Vicor bricks, and they are good up until you get near 90% max - then they heat up. Good luck! Peter ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
On Tue Oct 07 21:36:58 PDT 2014 ev@lists.evdl.org said: Ah, I think you pointed out the issue: the brake vacuum pump. With all the other stuff on, I'm running around 40A without touching the brakes. The car battery can handle the surge current for the brake pump. I will be checking the DC-DC temp tomorrow. (ran out of time to fiddle with things tonight.) -- Bobcats and Cougars, oh my! http://john.casadelgato.com/Pets ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
On Tue Oct 07 21:33:02 PDT 2014 j...@ecoreality.org said: Don't suppose you could run your brakes and steering from mechanical pumps coupled to your drive motor? That would be more efficient, and save you a bit of range. That's what I plan to do in the conversion I'm working on. Somehow, I doubt that running the brake vacuum pump continuosly, when it's not needed, is more efficient. As for the Power Steering pump, generally you need the most power from that when you are moving the slowest. Mechanical ones are always pumping fluid, and just letting it flow back into the reservoir. Hardly efficient. The 12V one only draws a few amps when idling. I agree with others that the parallel Vicor modules may be fighting with each other. Are they adjustable? If so, you could sum them via a Schottky isolator, but it will drop about 0.2 volt, which you'd probably want to adjust out. Already doing that. Actually, I'm seeing a bigger voltage drop across the 30A fuse on each module than I am across the diodes. -- Tigers prowl and Dragons soar in my dreams... ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
[EVDL] DC-DC Cooling
I think I'm going to have to figure out how to water cool my DC-DC. I built this one using 4 Vicor 20A bricks to get a 80A capable unit. It all fits on the back of a 6 square 2 thick heatsink with a 6 fan on it. I'm noticing that when I'm running 40A continuous load, the output starts becoming erratic. Ther fan on the heatsink doesn't seem to be enough when I'm drawing a lot of 12V power. (blower, lights, brakes, etc..) -- Try my Sensible Email package! https://sourceforge.net/projects/sensibleemail/ ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
Have you measured the temp on any of the units? It is possible that one of the bricks is not behaving. Failing that, you might want to redo the heatsink with some serious extruded aluminum. Cheers! On 10/6/14, 4:21 PM, John Lussmyer via EV wrote: I think I'm going to have to figure out how to water cool my DC-DC. I built this one using 4 Vicor 20A bricks to get a 80A capable unit. It all fits on the back of a 6 square 2 thick heatsink with a 6 fan on it. I'm noticing that when I'm running 40A continuous load, the output starts becoming erratic. Ther fan on the heatsink doesn't seem to be enough when I'm drawing a lot of 12V power. (blower, lights, brakes, etc..) -- Try my Sensible Email package! https://sourceforge.net/projects/sensibleemail/ ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
On Mon, Oct 6, 2014 at 7:21 PM, John Lussmyer via EV ev@lists.evdl.org wrote: I think I'm going to have to figure out how to water cool my DC-DC. I built this one using 4 Vicor 20A bricks to get a 80A capable unit. It all fits on the back of a 6 square 2 thick heatsink with a 6 fan on it. I'm noticing that when I'm running 40A continuous load, the output starts becoming erratic. Ther fan on the heatsink doesn't seem to be enough when I'm drawing a lot of 12V power. (blower, lights, brakes, etc..) I used a Vicor Megamod on one side of a 1/16 aluminum sheet and a Batmod with a simple control circuit cookbooked from the Vicor app notes on another sheet on the other side. In between I had a triple ro w of 1/8 copper tubing doing a serpentine thing between the two . Inlets and outlets were done with a little 3-into-1 collector into some 3/8 copper tubing. Everthing was JB Welded together. With 1/8 standoffs around judiciously placed screws, it all remained very flat and sturdy. Very compact for its power. It wasn't a quick build, but fairly straightforward. Unfortunately I never ran it at the loads you're pulling, but if that's a concern you could go up in size. You probably have room for that in your truck. I didn't in my car. Chris -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141006/43b464f5/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] DC-DC Cooling
On 6 Oct 2014 at 16:21, John Lussmyer via EV wrote: The fan on the heatsink doesn't seem to be enough when I'm drawing a lot of 12V power. (blower, lights, brakes, etc..) I'm not an engineer, but I think one of the problems with using multiple DC:DC converters is balancing the load. You might try putting a (good sized) ammeter on each individual Vicor to see whether they're playing nice, or whether maybe one is trying to handle too much of the current. Just a thought. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
