|
Maybe have an option to add an MR2535 to dump any voltage spikes?
As for running them for 20 minutes,once the current stabilizes (maybe up to a few seconds depending upon that load) the rest of the 20 minutes does not do much.
Switching it at max current rating (at room temperature) a couple hundred times would be a cheap way to find weak units much more effectively. You can build during the day, then test at night using a PC, a National Instruments card and a power supply. It is a very effective (for a generic test).
Anyone who has done any level of engineering will tell you that, for a given price, in order to add something to protect one person from his lack of common sense, you have to take away from part of the product that truly effects reliability. I could, of course, charge all of my customers for a nearly useless feature that none of them would use, since the majority of them don’t connect 12V to a ground wire. I kind of doubt though that they’d want to pay for that anymore than everyone would want to pay for 6” thick television screens so that you can play basketball in your living room. From my calculation, given the number of people who have blown them up this way, the part to protect it would have to cost less of a tenth of a cent for my customers to break even. I’m pretty sure that part is more than 1/10 of a cent. It would be nice if we could all live in a little obama world of nerf and free healthcare, but it turns out that someone else always has to pay for it, I take it you’re a democrat.
With regard to your reliability assessment, what you are proposing is testing for 100 random events out of an infinite possibility of events, it might make you feel all warm and fuzzy inside, but it has absolutely no useful utility. That is why that part of reliability analysis is always done at the design, not the test level. I've done failure analysis on a line that shipped 50 million a quarter, believe me when I tell you that what you're saying with regard to this is incorrect.
I don't care what anybody says, this product is kick ass!!!
Nobody else makes anything like it and if I had been smart and fused the power going to the module it wouldn't have fried when I got a stick jammed in the fan(it's a long story).
Yes, it took quite a while to get it shipped but it was well worth the wait.
Baskin it's nice to see you on here, now how about a deal on another module?
While I'll also say mine took a while to get here, I hooked it up yesterday! Two days of driving so far with it working perfectly. I'm impressed so far, thanks Brian!
I've had my FK35 for about 2 1/2 years, and it's been flawless. I don't have to worry about it at all.
Mines been on a rather rabused buggy for 3-4 years now. It's exposed, and has been submerged more than once, things it wasn't even designed for - yet it just keeps on working.
Great product in my opinion.
Being a certified Reliability Engineer at a premier aerospace/avionics company, and doing the Reliabilty analysis you talk of and plan for production, field support and test, yeh I know what I am talking about.With regard to your reliability assessment, what you are proposing is testing for 100 random events out of an infinite possibility of events, it might make you feel all warm and fuzzy inside, but it has absolutely no useful utility. That is why that part of reliability analysis is always done at the design, not the test level. I've done failure analysis on a line that shipped 50 million a quarter, believe me when I tell you that what you're saying with regard to this is incorrect.
If you product works to the level your customers need great.
By the way agriculture and some heavy engine outfits use an MR2535 on all there electronics in case of batteryless operation, alternator diode failure, reversing wiring etc... It has been a while but John Deere and Caterpillar required them (or similar protection scheme) or all there equipement that hangs of any main bus power (12V, 24V, 48V).
The only reason I quipped up in here is you claimed that 20 minutes run-in equal zero problems which is not true.
I am about to install a DCC 2SP with a Ford Taurus Fan. What size fuse should I use for the high speed (high fan)? Is a 40 Amp enough?
Thanks
when i measured my taurus fan amperage the high speed spiked at 120amps on startup and ran 40 amp continuous, a fuseable link will be a better solution for the high speed protection
I'm pretty sure the DCC comes from Brian with a fusible link for the hot lead. Been a while since I put mine in, but I'm fairly confident there.
I've had my controller in for a few years, and it just now is having some issues that are more than likely due to a failing temperature probe. Order is in to DCC for a new probe, then I'll slap the Taurus fan back in. Mechanical fan for now so I can get smog test done tomorrow.
Electric motor startup typically will hit a 6X peak current at start up but it is short in time (<<0.1 sec typical). Also on shut off there is a reverse voltage spike. (V= L dI/dT or Voltage = motor inductance x change in current over change in time). A big relay works.
The start up is more to due with heat generation of the contact points on the relay. A cheap relay cannot dump the heat and well designed and built one can.
A reverse diode for the reverse voltage shut down can dump the current of the coil in shut down. Sometimes a cheap relay cannot take the reverse voltage spike.
I am going with a MOSFET and a reversing diode instead of a relay. It also needs a couple small parts, a gate drive zener and bead on the gate.
A power MOSFET can be had with less than .05 ohm so at maximum 30 amps out continuous it only sees 1.5 watts loss. With a small heat sink (just an aluminum channel) this gives less than 10 degree rise junction to ambient. So worst case with the engine compartment=70oC the junction would be 80oC, and is spec'd to 150oC.
When I installed my fan I grabbed a bunch wiring and the fuse holder from the car I pillaged it from at the wrecker. I used the original fuse and holder in my install. I believe its a 60amp maxi fuse.
I guess I got the wrong fan from the Junkyard the other day. I got the dual fan set up from a Taurus, will those work with this setup too? Or do I need to go back and find the single bigger fan?
Wow, don't know how I missed a bunch of rando's without Grands posting on here bitching about a product that we all seems to love. Anyways, I ordered up the 2sp relay controller and will be installing it here shortly as everyone that I know that has Brian's products loves them.
Just order asap. Takes forever to ship...
Sent from my iPhone using Tapatalk
« Previous Thread | Next Thread » |
Thread Information |
Users Browsing this ThreadThere are currently 1 users browsing this thread. (0 members and 1 guests) |