Any beefy coil driver chips?

I _promise_ not to laugh ;-)

...Jim Thompson

go

and so

too.

driver

pump.

I was simply asking if anyone knew a nice chip that I might have overlooked.

Me? Never. You should know me better by now :-)

In the 90's a client gave me a "Notis to Contrackers: Contracker is s'posed to be kerrectin' what's drawed wrong and not make fun of da enginear, or laugh or smile ..." or something like that. I don't have it anymore and a web search went empty. Anyone know if it's posted anywhere?

Sounds like something I want for my wall art ;-)

...Jim Thompson

Why is that timing so important? Most mechanical stuff is in the msec range anyway. If its driven by a relay contact timing can't be very tight.

A GAL16V8 or similar? I still think an NE555 solution is the easiest.

I think there was more such fun making in electronics in the 90's than today. Yesterday I needed to look up something on my pulse pattern generator. Grabbed the service manual, found a cartoon page. This thing was engineered in Sweden where I'd never have expected that.

This one is tight, got to go by the specs given me ;-)

Yeah, no gas guzzler devices. A 555 type is nice but there are some buck and boost chips that have more analog on board and could possibly find an unorthodox use here.

Reminds me of a WAI (wild-ass-idea) I have ruminating in my head: What would it take to record say a 500-bit stream of a data pattern on a CD, then play it back on an ordinary cheapo CD player modified to simply spit out 5V logic levels? Use: Poor man's BER tester. How would you do that?

...Jim Thompson

I assume you would have to hang a fast comparator (or maybe a Schmitt is enough) to the output of its RF amp:

However, I do not really know what the storage format is, where the Q-codes are hidden and so on. There should be hack sites for that though. If it is to be spitting out permanently you'd also have to either record the whole CD full of repeated sequences or mess with the miror and tracking circuitry. But then I wouldn't know how to record because your CD writer won't do that.

Why not just use a fast FPGA?

I think I can do it with one NAND schmitt trigger section, 2 Rs, 2 Cs, driving a mosfet.

John

Show us, John ;-)

...Jim Thompson

Seriously, it ain't quite that easy. Just one of the nastier effects: Such lines can hang, rattle, sizzle, and then you get serious undervoltage coming in for a while, FET tries its darndest to hang in there ... *PHUT* ... red lights flash, sirens wail ...

You have to be careful on what those specs actually represent...

Back when I was working on the 91 Express lanes, we needed a gantry above the road to hang all the electronics from. My boss had just used a swag or height +/- 1" on the allowed vertical movement of the mount points.

The mechanical guy designing the gantry came back, and said the best he could do was +/- 3", and would that be ok.

So, he comes to me, as the actual engineeer on the thing, and asks me if that will work. I take a look at the sensors, do a quick calc, and say "I could actually handle +/- 6"!"

He says "Never tell the mechanical guy that!"

So, if you ever wonder why they have that monster gantry across the freeway... ;-)

Anyway, moral of story: Sometimes a spec is actually a SWAG, and has no real bearing on the actual requirements of the system!

Charlie

Jim Thompson a écrit :

CPLD

Short it.

and then ... phssst ... *BAM* :-)

Then it holds, if you're lucky.

Seriously, with a pair of switches you could do that but I just realized you want hold from brief to, hum, hours... You could still make your coil supraconducting :-)

Where's your load (coil) attached? If it's to the supply line, then you could use the ubiquitous 3842/45 Enough pins to coax it to do what you need and I've used it in nearly the same app.

But in this case it would cook out. Must ramp down quickly after the relay is engaged.

:-)

That's still up to me. Luckily ...

I am still looking at switchers but these are only 1A abs max and the

Fuel injector driver like a LM1949, obsolete. Actually I cannot find anything compatible.

Cheers