Another Horn Question-74 Cj5

The links to mouser.com for example. I can't get any of your links to mouser.com to open.

 

I don't know. They work perfectly for me. I have to clip the https off the front and lead the link with www.mouser.com or the forum hangs when I submit the post.

Try this - tinyurl.com/6ja48bam

Again, I have to clip off https:// or the forum hangs when I submit. I am blocking tracker cookies from twitter and facebook.

If I cut and paste the original link into a new window, it prepends http:// and goes to the site. There Mouser changes it to https:// (secure link, encrypted transmission I presume).

 

Don't know what to tell you. I can go directly to mouser.com and your link above to their website works. Was just having trouble opening your other links to mouser.

 

Huh. I can't interpret the long string in these links. Maybe Mouser is doing something with the URL to prevent others from following it.

You can take the part number from the Mouser link, like L7805CV or LM340AT, and put it in the search box at the top of the Mouser site. That will take you to the part.

 

They let you make a BOM (bill of materials) aka "project" on the site. I made this BOM - see if you can go there.

www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=8fafaa72ce

Same problem with the forum. It hangs if I include a link with https:// proceeding it.

Try this Digikey link -
LM340AT-5.0/NOPB Texas Instruments | Integrated Circuits (ICs) | DigiKey

If that works I can go back at some point and replace the Mouser links with Digikey.

 

Won't matter in this application.

 

The links are working, also the earlier links are working now..

 

I am reading and studying your post. I have been practicing my soldering skills without much luck to begin with, But I am improving. Bought some alligator clamps to make myself a holding jig for the wires and a heat gun for the shrink tubing.
I am going to make sure I am reasonably good soldering before I order a Linear Voltage Regulator. Will post a photo or two when I get started if I can improve my solder well enough. Right now though I am to embarrassed for anyone to see it.

 

You should see my arc welding skills.... When I take a picture, it's usually 10 feet away so you can't view my weld.

Maybe we should post pictures of some of our, not so elegant, soldering. That way you won't feel so bad.

Keep practicing. You'll get it.

This is kinda like "Give a man a fish" vs. "Teach a man to fish."

 

My bench top is MDF, and I would just lay the part on the bench - no holder needed. I'd tin the wire and hold it next to the lead on the part and apply the iron. They should fuse together in literally a second? Not long. You should be able to hold the wire in your fingers and it won't get hot.

Doing this under the dash will be harder. There you really need to secure the joint with a connector or whatever before you apply heat. You won't have as much control over position of the joint and gravity.

With semiconductors, it's good technique to solder quickly. One could buy special clip-on heat sinks to go between the joint and the part, but you should not need them if the joint is clean and properly prepared. The typical 3-legged transistors (TO-92 package), and even the tiny SMD packages can go in the board or whatever and be soldered in place, no extra prep needed. A little extra flux helps, but should not be needed if the joint is clean. There should be enough flux in the solder core, but you can add more. Try it - it's easier than you imagine.

I have smaller solder on my bench than in the garage. If you are going to use one roll for both, buy the smaller size and just feed in more for bigger joints. Not as convenient, but the large solder wire will be too clumsy for soldering circuit boards and such.

What kind of soldering station are you using?

 

If you are soldering under the dash, wear some eye protection.
Sometimes the tension in the wire might spring the connection apart splattering solder.

I usually tin the wire and the lead on the IC. As Tim says, it takes just a second to reflow he solder and make a joint.

Don't forget to put the shrink tubing on and well away from the area you will be soldering.

Since you are beginning, I would make sure he two parts are secured in positioned right before applying heat. At least one part should be secure in place so things are not floating around and you are chasing it with the iron. .

 

Thanks for the advice, I have soldered copper pipe before but this small wire soldering is entirely different with new problems. At first I was using some large solder I had for tubing, that was lead free, found it east to get too much solder on the joint. No matter how well I cleaned it and used flux I had cold joint problems. Next lesson got some lead solder like 60/40, worked 10 times better. Switched to a smaller point on my solder gun too. The solid solder with plenty of flux seemed to work better for me than the flux core solder . i have some small clamps that I mounted on the edge of a piece 2x6 board. I clamp the 2x6 in my bench vice for a work station. Been practicing joining some 18 gauge stranded copper wires and also joining the stranded wire to some solid 20 gauge or so solid copper wire that I had hammered slightly to flatten it. Sort of an improvised lead or pin like the ones found on a 7805VR. I am improving in my skills for sure. A little more practicing this weekend and I will attempt the real thing I am thinking I will remove the speedometer completely for the installation work. Maybe mount the VR to one of the screws on back the speedometer to begin with so it will not move around. Thanks all, I will try post some pictures when I start.

 

Yes, removing the speedometer will make mounting it easier.

Make sure you label everything. But if you forget, we can straighten it out for you.

It would be a good idea to test it before reinstalling it.
Do you have some resistors to test it out with? I might have a couple I can loan you to test it out.


I have a video of the original CVR operating at different voltages if you are curious.
I ran it from 6 to 24 volts to see if the regulator would still work.
Best to view it in full screen mode.



You are looking at the signal on the "A" terminal.
You can see the pulses getting narrower as the voltage goes up. You can also see the height of the pulses increase as the voltage goes up.

You get a pulse every time the regulator closes. When it's closed, the heating element around the bi-metallic strip heats up and bends the strip breaking contact. That's the lower part of the trace.

What really surprises me is how fast the regulator responds to such small pulses.

 

Nice scope. That's got to be at work - not many people can justify a newish $3000 scope on their bench at home.

That scope probably can integrate what's between the cursors. Looked for that on the display and did not see a number for that. Don't know what buttons to push to do it, but it's probably available.

Just a comment - I would assume the extended performance of the CVR at a voltage less or more than 12 to 16 volts is coincidental, not intentional. The 7805 IC will continue to work too at range from about 7 volts to 35 volts. As a linear component, it needs a couple of volts above output for the supply to maintain regulation. Even then, it's throwing away the excess voltage as heat. At 35 volts (max spec sheet rating), it's still regulating but throwing away nearly 3x the heat that it would be at 12 volts. (more than 4x, not 3x ... I forgot to subtract the output voltage).

In that way, the CVR has more in common with the little switching supply that John linked to above. The switcher changes the DC into a high-frequency AC, which in this case is stepped down with a transformer to 5V and rectified ( a "buck" convertor - switchers can also be "boost" supplies). Still takes some power to run, but more efficient than a linear supply. These supplies run at high frequencies because the transformer size can be very small at high frequency. This design comes at a cost of lower durability and reliability, more complexity, higher cost, and a bunch of low level rf noise. Your computer power supply is a switcher, and the inside of the computer cabinet is alive with rf junk from the supply and the buss traffic.

Not arguing though, the switcher will work in this application. If you have a problem with radio noise you can filter it out. I expect rf radiation is why it's contained in that aluminum box, so that any noise only comes out on the wires, not radiated from the electronics. It may also be waterproof, dust proof etc. but that's likely coincidental to the rf shielding.

 

Yep, its at work. we inherited 20 of these from another division. We only have 3 techs. So as soon as they scrapp one because they can't meet there yearly calibration, I may grab it out of the dumpster...
I got 5 of the older Tektronix analog scopes that they were auctioning off for only $1.00 a piece.

The scope was set at 250 mSec per division. 10 Divisions for the full width or about 1 full sweep every 2.5 seconds.
I was going to do some more measurements but notice a broken wire going to needle movement side so I could not continue before work started.

I managed to tie them together, I can't seem to solder nichrome wire, and got it working.

 

I have tried to solder nichrome and failed. The resistance wires in later Jeeps (ballast, exciter) are nichrome and are only held in with a crimp, as far as I can tell.

The shortest width of the pulses from looking at the trace is about 60 ms. This seems short compared to the cycle time, but seems unremarkable to me. For perspective, that inexpensive little latching relay I pointed to in another thread has a latch-up time of 10 ms.

 

Well gentlemen I have become confident enough that I may be able to solder up my LVR, capacitors and associated wiring. After much study of your post, comments and discussion links I have attempted to make a list of parts I feel that I will need to complete the job. I have below an order list at Mouser. Please take a look and let me know what you all think. Have I selected the correct parts? Anything else I should add?
I did include two 47 ohm resistors to test my gauges with when finished installing my LVR. Wired in parallel together they should produce about 23.5 ohms. Close enough to place either gauge about mid scale. The rest of the values I will leave up to the sending units. Thank you very much for your help and patience with my questions. Jim



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81-RDER71H104K0M1H3A
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Multilayer Ceramic Capacitors MLCC - Leaded 0.1uF 50volts X7R 10%
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I picked up this small roll of solder at the flaps today. Is this good for my LVR project, looks kinda small in diameter.

 

It should work. 60/40 is ok. 63/37 is good too, probably what I'd pick. You want small in diameter.

Likely expensive for what you get: https://www.amazon.com/KESTER-SOLDER-32117-24-6040-0027-Diameter/dp/B00068IJPO/ref=sxin_10

Does it give a diameter? I have 30 and 15 thou on my bench, 50 thou in the garage.

 

The diameter was not given as best I could see. But I think it is about .015 or so. And yes it was 8.00 for that small package . Maybe enough to solder the pins on my LVR project. Oh, Tim did you see my earlier post with the parts order?