4
\$\begingroup\$

I am modifying my intercom phone by adding an on/off switch for the intercom doorbell outside. The live wire of this doorbell is connected to a pin on a circuitboard and looks like this:

enter image description here

According to ChatGPT this is a female spade crimp connector. But this connector is connected to a pin, not a spade shaped connector. Does anyone know the name of this crimp connector? I'd also like to know if perhaps i could use a different kind of crimp connector to attach to the pin on the circuit board. Here's a photo of the opened intercom phone. The pin is indicated with a blue arrow.

enter image description here

EDIT: Here's a close-up of the round pins on the circuit board. I've also added a second photo of the crimp connector, showing the back side.

enter image description here

crimp from the other side:

enter image description here

I'll also add that this house is very old, including the circuit board. The house was built in 1982. Back then they still used brown as the color of circuit boards. It could be that this particular crimp connector is no longer made. If that's indeed the case, does anyone know a good alternative crimp connector that can fit on a round pin with a bullet shaped end?

EDIT 16/10

I've measured the diameter of the pins. I believe they are 1 mm in diameter (i measured pin 9, see photo). I've also added a clearer photo of the pins that was taken from the side. All pins are about 4 mm to 5 mm in length.

enter image description here

enter image description here

\$\endgroup\$
9
  • \$\begingroup\$ It might be hard to identify the connector itself, but could you measure the diameter of that round pin it's meant to fit over? There are dozens of manufacturers of connectors to mate to round pins, and it should be easy enough for us to identify one that will work, even if it's not the same exact part as the original. \$\endgroup\$
    – Hearth
    Commented Oct 15, 2023 at 17:49
  • \$\begingroup\$ I think a shot of the connector from the mating end would help to show it’s not a true spade connector \$\endgroup\$
    – Bryan
    Commented Oct 15, 2023 at 18:11
  • \$\begingroup\$ @Hearth, I don't know the exact diameter of these pins. Could you give me some suggestions of modern connectors that mate with round pins? I also need a male version of such a connector. \$\endgroup\$
    – Maurice
    Commented Oct 15, 2023 at 18:18
  • \$\begingroup\$ @Maurice Do you have calipers? Maybe even just a ruler? Measure them. I know Mill-Max and Preci-Dip make round pin connectors that would probably work, I just can't suggest a specific part number without knowing how big the mating pin is. \$\endgroup\$
    – Hearth
    Commented Oct 15, 2023 at 19:33
  • \$\begingroup\$ @Hearth, ok i'll measure it tomorrow. \$\endgroup\$
    – Maurice
    Commented Oct 15, 2023 at 20:50

4 Answers 4

1
\$\begingroup\$

While I can't identify the exact connector used (which appears to be some unusual one designed to mate to both faston-style flat blades and round pins), I can suggest some connectors that will mate to the pins on this board. Since you say they're "1 mm in diameter" (looks like a bit more than that in the picture, though...), here's a connector that will work for pins in the range 0.813 to 1.168 mm (0.032 to 0.046 inch), to be crimped or soldered onto 18-22 AWG wire.

If you have smaller wires, this one is for the same range of pin sizes, for 22-26 AWG wire. It's also a bit cheaper.

Since it looks to me like the pins are a little larger than 1 mm in diameter, here's another connector that's designed for pins in the range 1.143 to 1.651 mm (0.045 to 0.065 inch), for 18 to 22 AWG wire. And again, here's the equivalent for 22-26 AWG.

I found all of these using Mill-Max's product finder, which is very handy when you need some pin receptacles like this.

Disclaimer: I have no affiliation with Mill-Max beyond as a customer; I've just used their parts a lot in the past and know how to navigate their website to find suitable parts. You should be able to find similar parts from Preci-Dip as well, and probably a handful of other manufacturers, if you prefer.

\$\endgroup\$
8
  • \$\begingroup\$ Thanks a lot Hearth, I really appreciate it. I do have a few questions about the suggested connectors in your post. Firstly, Can I attach these connectors to a cable with regular pliers as well? I was thinking about simply inserting an uninsulated end of the cable into the connector and then use pliers to flatten the connector a bit so that the cable remains stuck inside. I also have some conductive copper tape that i could use to attach the connector to the wire. Secondly, which male connectors would you recommend that would fit into the unusual female connector? A blade or a pin connector? \$\endgroup\$
    – Maurice
    Commented Oct 16, 2023 at 13:26
  • 2
    \$\begingroup\$ @Maurice You really shouldn't use pliers to crimp anything, use a proper crimping tool. Pliers won't make a reliable crimp; it'll either be undercrimped and liable to develop a flaky connection over time, or overcrimped and liable to break. If you don't have a crimp tool, these can be soldered as well. Copper tape is absolutely not suitable. I recommend sliding some heatshrink over them after crimping or soldering. For the male connector, I suppose I would use a standard QC terminal as they're cheap and easily available. Just make sure you get the right size. \$\endgroup\$
    – Hearth
    Commented Oct 16, 2023 at 13:32
  • \$\begingroup\$ @Maurice Undercrimping is more than just not making a connection: a properly done crimp produces what's called a "gas-tight" connection between the wire and the crimp terminal, where the metal is effectively cold-welded together so that no air can get into the interface. This is important, because while copper is fairly resistant to oxidation, it will oxidize given time and exposure to air, and if you get copper oxide in the interface, it will interfere with the connection. You can get what seems like a perfectly good crimp that fails a year or two later. \$\endgroup\$
    – Hearth
    Commented Oct 16, 2023 at 13:40
  • \$\begingroup\$ @Maurice The danger of overcrimping is perhaps more obvious: Deform the metal too much and it will break. Again, you can get what seems like a good crimp that then fails a few years later because your overcrimp wasn't enough to directly break the connector in two, but it was enough to create micro-fractures that slowly grow with vibration and thermal cycles until the connector does break in two. If you don't have a crimp tool, soldering is probably more reliable; you can't really "over-solder". Just make sure you use electronics solder, not plumbing solder. \$\endgroup\$
    – Hearth
    Commented Oct 16, 2023 at 13:44
  • \$\begingroup\$ @Maurice Lastly, I suggest heatshrink both for aesthetic purposes (it looks cleaner) and practical ones--it provides a small but nonzero amount of strain relief, transferring forces applied to the wire away from the (relatively weak) crimp or solder joint. \$\endgroup\$
    – Hearth
    Commented Oct 16, 2023 at 13:45
3
\$\begingroup\$

That looks like a combination barrel/quick disconnect terminal, or perhaps just a barrel terminal with the "wings" there to give extra springiness to the contact surfaces as in this TE terminal. It is definitely not a spade terminal, which has two forks that slide around a screw shank. I cannot find examples of currently manufactured exact replacements but I'm confident enough to post this as an answer. Replace with a barrel terminal appropriately sized for the pin diameter.

Edit: "pin terminals" might also work but be careful: the vast majority of them look like they're designed to go into a specific housing.

\$\endgroup\$
3
  • \$\begingroup\$ Would a female bullet connector work as well? \$\endgroup\$
    – Maurice
    Commented Oct 15, 2023 at 18:15
  • 1
    \$\begingroup\$ Bullet connectors are probably not the same size as your pins and also are shaped with grooves that lock into ridges on the inside of the receptacle but if you can find one that fits snugly it should work. I recommend getting a fully insulated version with plastic all the way over the metal so if it does pop off it's much less likely to accidentally make electrical contact with something it shouldn't. \$\endgroup\$
    – vir
    Commented Oct 15, 2023 at 18:20
  • \$\begingroup\$ I agree: definitely not a standard blade connector, probably proprietary and unstandardised. The best way of dealing with this is to cut the wire some distance from the connector and solder it to a replacement with heatshrink. However since this is mains voltage IS IN DOUBT CONSULT A CERTIFIED ELECTRICIAN. \$\endgroup\$ Commented Oct 16, 2023 at 5:58
2
\$\begingroup\$

From that angle, the part shown in the photo looks like a female quick-disconnect terminal. The AMP (Tyco) name for this is Faston. It slides over a blade or tab.

Squinting at it, I can see where it could fit over a round pin. Autosplice is (or was) a big name in this type of connector.

Overall, I think the tab style is more common. I don't know if the pin type has a generic industry name.

\$\endgroup\$
2
  • 2
    \$\begingroup\$ It does look like the PCB has a round pin, rather than a flat blade. So far, haven't identified a crimp connector designed to mate with a round pin. \$\endgroup\$ Commented Oct 15, 2023 at 17:47
  • 1
    \$\begingroup\$ @ChesterGillon, yes these are all very small round pins. \$\endgroup\$
    – Maurice
    Commented Oct 15, 2023 at 18:19
0
\$\begingroup\$

It's hard to tell from your photos but I'm thinking this is something we call a "Fast-on" connector. These come in several widths: 0.125", 0.208", 0.250". The 0.250" version is what we use the most of but we keep all the other sized in stock for use when necessary.

\$\endgroup\$
3
  • \$\begingroup\$ Is 0.250" also used most on circuit boards? \$\endgroup\$
    – Maurice
    Commented Oct 15, 2023 at 18:19
  • \$\begingroup\$ @Maurice It's probably the most popular size of this type of connector in general. I use 0.250" and 0.187" ones all the time, and a former coworker was a fan of the 0.110" size. I've never used the 0.125" or 0.208" sizes. Note that none of these will work for your particular use case, however, as standard ones are only for flat blades, and will not accept the round pins you show. \$\endgroup\$
    – Hearth
    Commented Oct 16, 2023 at 12:29
  • \$\begingroup\$ @DwayneReid Note that your list of sizes is not complete; I know for a fact that 0.187" and 0.110" sizes exist as well, and there's the rarely-seen extra-large 0.375" one. "Faston" is an AMP/TE brand name; compatible connectors are also made under different names by the usual suspects: Molex, Panduit, 3M, and so on. The generic name I usually see used for them is "quick-connect" or QC. \$\endgroup\$
    – Hearth
    Commented Oct 16, 2023 at 12:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.