Recent content by bryanb

A late welcome from your 2013 Gen 1 neighbor in Tyler!

Xanax?

I don't think I said anything about "low voltage" but I did make a distinction between high and low current (amperage). The current through the diodes in your picture will be quite high. My advice is not to build what you drew.

I modified my diagram to add your "arming" function: The primary issue with your design is that you've put the diodes on the high current path. My diodes are all on the low current paths so they will be small and won't have thermal design constraints to worry about. If your light bar is...

Ok, now I know what you are asking. The answer is you need diodes for both of the cases I originally described. You can use the same readily available 1N007 diode for all three diodes below. You're getting lots of different advice including that diodes aren't needed at all. That may be right...

I'm sorry! I'm an electrical engineer so it's rare I can say anything knowledgeable here. Sometimes I get carried away. I was, however, telling my wife and daughter at the dinner table last night about the exciting diode discussion we were having on FRF. They think you are all nerds like me now...

Hey, I think maybe two different diode use cases are being mixed in this thread. Is your question about: 1) Using a diode to protect against damage from the transient voltage created when power is turned off to a relay coil; OR 2) Using a diode to ensure current only flows in one direction...

Bench tested with what? A DC power supply or an auto battery? If you've just tested it with a DC supply, try your truck's battery. Most bench supplies won't provide the required current for such a large light bar, and the voltmeter telling you have power doesn't reflect that the internal LED...

Just a few more thoughts on the topic: The textbook answer is that electromechanical relays should always have suppression (flyback) diodes because the collapsing magnetic field in the coil when power is removed generates a high voltage across the terminals of the relay and this can damage the...

I have to agree about competition. This is the kind of thing grown ass men should be swapping barbs over rather than the topics that dominate life in America of late. And I would much rather have Dodge defacing their truck with schoolboy graffiti than watch another Prius commercial telling me...

This was (almost) my first reaction too, but in North America, California holds the title. 50% more in Taxachusetts isn't 50% more compared to most parts of the country including AZ. Sounds like the OP has friends and family connections to MA and that's worth something, but I spent some time on...

I don't entirely disagree with your point. But the difference is that, on the road, I am just one of many others and assuming I'm driving courteously I am not giving anyone any reason to pay a bit of attention to me. Also, once I drive by you, I am gone forever. And as careful as I am to not...

Probably for the same reason that nobody uses their real full name as a handle on this forum. :-) I love you guys, but I don't want you dropping by unannounced.

For mobile applications the answer is probably "no" if you are referring to VHF amateur bands. The antenna and modulation requirements are different enough that you'd end up with two different radios inside the "single" radio using two antennas so why bother. You'll notice that a CB antenna is...

Sweet! I think I spotted the secret to your success working in tight places. Tools needed for the install: Drill, various sockets, ratchet, whiskey, combo wrenches, pliers.