Hi Thanks for the answer my 93 year old neighbour and pal is currently building one as I am in my garage I will then get the grand kids to build one It will introduce them to soldering and some electronics I have a Mk 11 Jag and and E type I think the faulty ground on the Mk 11 caused the stabilizer to fail I have a new ground strap and a better negative battery lead and the car is now more reliable starting Cheers Mike Mississauga
Thanks for the shoutout, and you are more than welcome of course. :) And yeah, the circuit is cheap enough that polarity protection is definitely optional. However, the capacitors are not optional (good that you added them). And for a "bodge job"* it came out very nice. :) For those out there that are still rocking the positive ground vehicles, I would use a LM7910 instead (a negative 10 volt regulator). And connect it up the same way that you would the negative ground version. *A "Bodge job" in the electronics world isn't a sign of careless work, rather it is usually a fix on a board that has had its traces blown (or corroded) away, or a factory fix for something that got left out during the design phase. A nice looking one is a sign of skill.
Hoping my bodge job holds up! I don't know if the video did it justice, but these boards seem really poorly made. One of the reasons I drilled holes is because I was afraid the solder pads would lift right off! Thanks again for your help!
@@WegsGarage It'll do just fine, and anytime! :) And yeah, I've seen some horrific boards in my time, and upon occasion I've contributed to some of that horror myself. :) But that's not a bad board, it's the wrong parts and a poor soldering job on a perfectly fine board. And maybe I'm slow (and I certainly didn't expect this), but I finally see where they are actually soldering a through-hole part on a surface-mount board. Really? I'll be damned... Somebody needs their junior engineer badge confiscated and their butt kicked. Honestly, I don't know of a good way to recover from this. I'd have to check, but I don't think that is the correct footprint for a surface-mount regulator. And while I didn't spend a lot of time on it, there doesn't appear to be a good choice in a surface mount package that will perform as well as the LM7810. And so what I think may have happened is that they planned for a surface-mount package, and had the board made, but found out that there wasn't one available that would deliver the current needed and have a high-ish input voltage limit (the LM7810 can handle 30 volts at the input. 80+ volts of input protection is advisable in the automotive world. But 30 volts is a start... Think of it as your car runs on 12 volts for most of the time. But not always.) And it is an odd looking board to be sure. Almost like it has an extra layer sandwiched in the middle. It's also a fairly translucent board, and it looks like it's actually a knockoff of FR-4 material (the green PCB boards). But boards come in just about any color these days so it's hard to say. I would be very interested in knowing what the original part was. It had a heat shrink sleeve over it. If you could remove the sleeve on the dead part and share the part number that would be tamp down my OCD a bit. :) That, and my money is on Moss Motors sending you out a Positive ground unit instead of a Negative ground one. Exhibit "A" would be that they are flat out of Negative ground units at the moment, but have plenty of Positive ground ones on hand. And the two different units pretty much look identical. :) Which would explain why it blew up. Getting back to my post a few weeks ago on the original install of the regulator, I would like to know why your lights, wipers, blower, etc. appear run through the instrument regulator? Or are they not, and your battery is about shot? Which would explain the need for jumper cables. In other words why the massive voltage drop? Keep in mind that your 7810 is limited to 1 amp (and that is with a heatsink - which you don't have). Beyond that and it will go into thermal shutdown.
This has been a common mod for many 'classic' cars since the early '90's. Typically all use the 7805 or 7810 regulator chip. The problem with these regulators is that if the ground on the IC opens up you get full input voltage on the output. The other thing is the ''thermal" IVR applies a higher initial voltage to the gauge then as the strip heats up it goes down to the mean pulse voltage. This allows the gauge to rise to the indicated reading fairly quickly. Funny thing is, it's cheaper to make these solid state IC chip regulators than it is to produce the original style. You should bond that semiconductor to the case too. They get fairly hot. A long time ago when I made some I mounted it to the metal can with some thermal paste
Hi Wegs, I just finished building a positive voltage unit based on the TI LM2940 that fits in the original style case. I struggled for the first year of driving my TR4A with a sketchy temperature gauge only to finally give up an install a mechanical temp gauge. It turns out that the problem was in the voltage stabilizer, not the gauge. At least now the fuel gauge is accurate. Going on long drives is much less stressful now. I enjoy your channel, keep up the good work boys!!
Awesome! The sketchy gauge readings were the reason to switch to the Moss solid state unit in the first place, which of course failed later on. So frustrating! With so many things to go wrong on these cars, it is at least nice to know the instruments are accurate.
@@WegsGarage I’ll have to review your video on your voltage stabilizer video to see how you crimped the lid back over the circuit board. I am looking into buying the metal case to build more and have to figure out how to crimp the case around my printed circuit so it doesn’t look like I did it in my garage, LOL. I really enjoy you and your dad restoring your TR4. It reminds me of me and my dad restoring old cars. Great memories! Dave
It is so awesome! Used one in a college lab and could never go back to my old cheapo Radio Shack version. Worth every penny (except mine was a gift from my lovely and generous wife😃).
Great project, you must be a EE, my dad taught me about smoke running electronics, he was an Aero EE that built Canadian Satalittes in the 60's-80'S. As he said, no smoke in Space!!
Thanks,the aftermarket items nows days are cr@p this is very helpful as I brought a replacement for my TR4 here in the UK and it only lasted 1 day, time to go back to my school electronics and make a better one.
Good job. I especially liked your creative hole drilling for the regulator and capacitor pins. I built one of these for my TR6 and while it worked, it looked messy so I was happy to put the cover back in place. In looking at the original regulator on the failed unit (1:35), it looks to me like it was a used part scavenged from an old power supply. So if they didn't test it, it may have been blown in its original application. This is both funny and sad considering the 78/79 (+ output / - output) series of voltage regulators are dirt cheap and have been around for more than 40 years. Oh, and on a TR6, this regulator is mounted on the back of the speedometer. You need to be a gymnast or a monkey to get to it.
Thanks, I just converted the voltage regulator for my '73 Volvo to be solid state. I used the capacitors, but I wonder if they're necessary for this application, since the gauges are so slow-acting?
Hi I am trying to do this but I dont understand som things My units don't have the metalicstrip around the outer perimeter of the inside of the unit so I dont know how to bring things to ground Also what do you mean by the trace on the right side Is that a strip of solder that you placed Thanks Hope you get to see this Mike Mississauga
Not sure if some boards are different. There is a ground somewhere, so if you have a meter, try to figure out using continuity where the connection is made to the metal case. If you can't find it, you can always run a wire to the case itself from ground on the regulator..
Yes, the same capacitors will work. The sizing is not all that critical as long as it is relatively close. If you really want to get technical, there are probably some 7805 data sheets that have suggested sizes.
Hi Thanks for the answer my 93 year old neighbour and pal is currently building one as I am in my garage I will then get the grand kids to build one It will introduce them to soldering and some electronics I have a Mk 11 Jag and and E type I think the faulty ground on the Mk 11 caused the stabilizer to fail I have a new ground strap and a better negative battery lead and the car is now more reliable starting Cheers Mike Mississauga
Thanks for the shoutout, and you are more than welcome of course. :) And yeah, the circuit is cheap enough that polarity protection is definitely optional. However, the capacitors are not optional (good that you added them).
And for a "bodge job"* it came out very nice. :)
For those out there that are still rocking the positive ground vehicles, I would use a LM7910 instead (a negative 10 volt regulator). And connect it up the same way that you would the negative ground version.
*A "Bodge job" in the electronics world isn't a sign of careless work, rather it is usually a fix on a board that has had its traces blown (or corroded) away, or a factory fix for something that got left out during the design phase. A nice looking one is a sign of skill.
Hoping my bodge job holds up! I don't know if the video did it justice, but these boards seem really poorly made. One of the reasons I drilled holes is because I was afraid the solder pads would lift right off! Thanks again for your help!
@@WegsGarage It'll do just fine, and anytime! :)
And yeah, I've seen some horrific boards in my time, and upon occasion I've contributed to some of that horror myself. :)
But that's not a bad board, it's the wrong parts and a poor soldering job on a perfectly fine board. And maybe I'm slow (and I certainly didn't expect this), but I finally see where they are actually soldering a through-hole part on a surface-mount board. Really? I'll be damned... Somebody needs their junior engineer badge confiscated and their butt kicked.
Honestly, I don't know of a good way to recover from this. I'd have to check, but I don't think that is the correct footprint for a surface-mount regulator. And while I didn't spend a lot of time on it, there doesn't appear to be a good choice in a surface mount package that will perform as well as the LM7810.
And so what I think may have happened is that they planned for a surface-mount package, and had the board made, but found out that there wasn't one available that would deliver the current needed and have a high-ish input voltage limit (the LM7810 can handle 30 volts at the input. 80+ volts of input protection is advisable in the automotive world. But 30 volts is a start... Think of it as your car runs on 12 volts for most of the time. But not always.)
And it is an odd looking board to be sure. Almost like it has an extra layer sandwiched in the middle. It's also a fairly translucent board, and it looks like it's actually a knockoff of FR-4 material (the green PCB boards). But boards come in just about any color these days so it's hard to say.
I would be very interested in knowing what the original part was. It had a heat shrink sleeve over it. If you could remove the sleeve on the dead part and share the part number that would be tamp down my OCD a bit. :)
That, and my money is on Moss Motors sending you out a Positive ground unit instead of a Negative ground one. Exhibit "A" would be that they are flat out of Negative ground units at the moment, but have plenty of Positive ground ones on hand. And the two different units pretty much look identical. :)
Which would explain why it blew up.
Getting back to my post a few weeks ago on the original install of the regulator, I would like to know why your lights, wipers, blower, etc. appear run through the instrument regulator? Or are they not, and your battery is about shot? Which would explain the need for jumper cables.
In other words why the massive voltage drop? Keep in mind that your 7810 is limited to 1 amp (and that is with a heatsink - which you don't have). Beyond that and it will go into thermal shutdown.
This has been a common mod for many 'classic' cars since the early '90's. Typically all use the 7805 or 7810 regulator chip. The problem with these regulators is that if the ground on the IC opens up you get full input voltage on the output.
The other thing is the ''thermal" IVR applies a higher initial voltage to the gauge then as the strip heats up it goes down to the mean pulse voltage. This allows the gauge to rise to the indicated reading fairly quickly. Funny thing is, it's cheaper to make these solid state IC chip regulators than it is to produce the original style. You should bond that semiconductor to the case too. They get fairly hot. A long time ago when I made some I mounted it to the metal can with some thermal paste
Great video
Hi Wegs,
I just finished building a positive voltage unit based on the TI LM2940 that fits in the original style case. I struggled for the first year of driving my TR4A with a sketchy temperature gauge only to finally give up an install a mechanical temp gauge. It turns out that the problem was in the voltage stabilizer, not the gauge. At least now the fuel gauge is accurate. Going on long drives is much less stressful now. I enjoy your channel, keep up the good work boys!!
Awesome! The sketchy gauge readings were the reason to switch to the Moss solid state unit in the first place, which of course failed later on. So frustrating! With so many things to go wrong on these cars, it is at least nice to know the instruments are accurate.
@@WegsGarage I’ll have to review your video on your voltage stabilizer video to see how you crimped the lid back over the circuit board. I am looking into buying the metal case to build more and have to figure out how to crimp the case around my printed circuit so it doesn’t look like I did it in my garage, LOL.
I really enjoy you and your dad restoring your TR4. It reminds me of me and my dad restoring old cars. Great memories!
Dave
Another nice video to fix a common issue!
Thanks a lot and have a beautiful Christmas and stay healthy!
Greetings from Germany
Uwe
Thank you! Merry Christmas to you as well!
Oh man the Hako! Not messing around. That's a good soldering iron
It is so awesome! Used one in a college lab and could never go back to my old cheapo Radio Shack version. Worth every penny (except mine was a gift from my lovely and generous wife😃).
this was helpful, i dont do too much electronic stuff so i mixed up the wiring, didnt connect the capacitors to the ground
Great project, you must be a EE, my dad taught me about smoke running electronics, he was an Aero EE that built Canadian Satalittes in the 60's-80'S. As he said, no smoke in Space!!
Thanks,the aftermarket items nows days are cr@p this is very helpful as I brought a replacement for my TR4 here in the UK and it only lasted 1 day, time to go back to my school electronics and make a better one.
great ...thankssss.
Good job. I especially liked your creative hole drilling for the regulator and capacitor pins. I built one of these for my TR6 and while it worked, it looked messy so I was happy to put the cover back in place. In looking at the original regulator on the failed unit (1:35), it looks to me like it was a used part scavenged from an old power supply. So if they didn't test it, it may have been blown in its original application. This is both funny and sad considering the 78/79 (+ output / - output) series of voltage regulators are dirt cheap and have been around for more than 40 years. Oh, and on a TR6, this regulator is mounted on the back of the speedometer. You need to be a gymnast or a monkey to get to it.
Good job, fellas. Pricing that stuff out, yeah, looks like you could make a bunch of them for about $25. I'll have to look into that!
Thanks, I just converted the voltage regulator for my '73 Volvo to be solid state. I used the capacitors, but I wonder if they're necessary for this application, since the gauges are so slow-acting?
Hi I am trying to do this but I dont understand som things My units don't have the metalicstrip around the outer perimeter of the inside of the unit so I dont know how to bring things to ground Also what do you mean by the trace on the right side Is that a strip of solder that you placed Thanks Hope you get to see this Mike Mississauga
Not sure if some boards are different. There is a ground somewhere, so if you have a meter, try to figure out using continuity where the connection is made to the metal case. If you can't find it, you can always run a wire to the case itself from ground on the regulator..
Would this same setup work on a 6 volt system? Say 7+ volts in, 5 volts out.
can i use the capacitors you used in the 7805?
Yes, the same capacitors will work. The sizing is not all that critical as long as it is relatively close. If you really want to get technical, there are probably some 7805 data sheets that have suggested sizes.