Overvoltage protection

[Tony Stewart]

I wonder if 5v accuracy affects the Temp sensors as any series resistance might drop voltage with unknown current

 

[KeepItSimpleStupid]

Plugging pin 2 means glue, toothpick etc.

 

[Tony Stewart]

are they at least keyed for orientation?

If not M I C K E Y M O U S E

 

[Tony Stewart]

If key not possible then make cable adapters for both ends that are fixed for one end with mating connectors for other end with 2 pin and 3 pin keyed for orientation.

 

[ADWSystems]

You have pins 1,2 and 3 in one connector and 1 and 3 in the second. Can't you just plug pin #2?

Not quite. Pins 1, 2, and 3, and pins 1, 3 are wired. All three pins exist. If pin 2 is plugged the connector won't mate, the male pin is still there.

are they at least keyed for orientation?

If not M I C K E Y M O U S E

In three ways, the pins are not symmetrical, there is a key on the housing, as well as a latch.

I think the best Mickey Mouse fix is to protect the sensor from overvoltage. I'm working on the PTC/fuse and zener. Just waiting for the parts to arrive.

 

[ADWSystems]

If key not possible then make cable adapters for both ends that are fixed for one end with mating connectors for other end with 2 pin and 3 pin keyed for orientation.

Sorry buddy, not following you on this one. If you are suggesting modifying the stuff "in the box", I'm getting a no go on those solutions. So changing the chassis connectors and adding stuff in the box is out.

 

[Tony Stewart]

Sorry buddy, not following you on this one. If you are suggesting modifying the stuff "in the box", I'm getting a no go on those solutions. So changing the chassis connectors and adding stuff in the box is out.

Not changing , but rather adding adapters to box and sensor to force unique match and prevent mismatch.

----->>---->|>-->|>------
----->>-----|- ->|>------
----->>---->|>-->|>------

 

[KeepItSimpleStupid]

Not quite. Pins 1, 2, and 3, and pins 1, 3 are wired. All three pins exist. If pin 2 is plugged the connector won't mate, the male pin is still there.

lets say if socket #2 is plugged (Glue or toothpick), the pin won't mate with the other connector. Good. Cut pin #2 off. So, the connector without pin #2 removed and the socket plugged, can't mate with anything else.

 

[ADWSystems]

lets say if socket #2 is plugged (Glue or toothpick), the pin won't mate with the other connector. Good. Cut pin #2 off. So, the connector without pin #2 removed and the socket plugged, can't mate with anything else.

I can't even imagine how I would cut the pin off. The male pins (like the majority of connectors I use and have used) do not protrude from the connector. They are not built like electrical wall plugs where the pins protrude from the backshell.

 

[Tony Stewart]

Needlenose or hemostat clamp grab & twist or pin removal tool from backshell, is like a small slit plastic straw. 2 seconds.

 

[KeepItSimpleStupid]

Yea, we don't have a pic of your connector. These https://www.galco.com/buy/Amp/206151-1?source=googleshopping can be had in standard and reverse sex. A $20 tool removes these pins in literally seconds. Used from the mating side.

Some car pin removal tools work from the wire side.

The pin may not be removable. Use a Dremel tool and grind down the pin.

 

[Tony Stewart]

I was thinking of $3 pin removal tool selected for whatever shell to compress hook and remove pin easily.
https://www.csttools.com/product.cfm?pi=3496EAD5-0CB6-E9F9-C94B2ED20E29327E

 

[KeepItSimpleStupid]

Tony:

We really don't even know what sort of connector he's dealing with. Generally everyone seems so secretive about what connector to use. I got a bunch of Delphi connectors and removal tools for a project at home.

The D connector removal tools are basically disposable, but you can get D connectors with fixed pins.

For work, I just fell in love with the CPc's. The AMP tool was just fantastic. Insert over the exposed pin and push to release the retainers. Then push the plunger to eject the pin. All with zero damage and always re-useable.

All basically for building reuseable laboratory equipment. The stuff, I built, seemed to never get re-used. Generally, re-purposed in it's entirety.

 

[ADWSystems]

Yea, we don't have a pic of your connector. These http://www.galco.com/buy/Amp/206151-1?source=googleshopping can be had in standard and reverse sex. A $20 tool removes these pins in literally seconds. Used from the mating side.

Some car pin removal tools work from the wire side.

The pin may not be removable. Use a Dremel tool and grind down the pin.

I am not sure the manufacturer of the connector. But I do know it is solder cup and the pins are not removable. The connector is about 1/4" in diameter with three pins. Think of this connector, only very much in miniature with the OD = 1/4". Getting a dremel in to grind off the pin without damaging the other pins may be a long shot.
**broken link removed**

As I mentioned, I think the SMT fuse and zener will fit in the sensor backshell and protect the sensor just fine.

 

[KeepItSimpleStupid]

So, it looks like an XLR connector https://www.switchcraft.com/Drawings/d_m_series_cd.pdf . Order one to practice on. It also looks as if the innards might be retained by a screw. If it is, your in luck, I think.

 

[ChrisP58]

What is the gender of the powered and unpowered ends? This scheme will prevent the 3 pin male from being inserted into the newly formed 2 pin female, but won't prevent the 2 pin male from mating with the 3 pin female.

The contact insert on all of the XLR connectors that I have used have been removable by removing the screw in the side. The pins are fairly heavy, so don't try clipping them with a small pair of cutters. When you plug the unused pin of the female, you'll want to fill it flush with the top to prevent a 3 pin male from being partially inserted. Even if the pin tips make contact with the sockets, you will have a meltdown.

 

[ADWSystems]

What is the gender of the powered and unpowered ends? This scheme will prevent the 3 pin male from being inserted into the newly formed 2 pin female, but won't prevent the 2 pin male from mating with the 3 pin female.

BINGO! As previously stated, all three connectors on the chassis are the same. So modifying the control box power connector to be a keyed 2 pin does not prevent the 3 pin 5V sensor connector from being plugged into the 24V control box connector. In fact keying won't prevent the sensor from being plugged into the wrong spot.

The contact insert on all of the XLR connectors that I have used have been removable by removing the screw in the side. The pins are fairly heavy, so don't try clipping them with a small pair of cutters. When you plug the unused pin of the female, you'll want to fill it flush with the top to prevent a 3 pin male from being partially inserted. Even if the pin tips make contact with the sockets, you will have a meltdown.

That's interesting stuff, but not applicable since (a) the system is not using XLR connectors (the connectors look very similar hence the picture but about 1/3 to 1/4 the size) and (b) keying won't help or prevent anything.

I said it "it looks like that connector". It is not that exact connector. It is not an XLR connector as shown tin the example picture. The connectors I am dealing with are only 1/4" in diameter, an XLR is about 3 times that large.

 

[ronv]

BINGO! As previously stated, all three connectors on the chassis are the same. So modifying the control box power connector to be a keyed 2 pin does not prevent the 3 pin 5V sensor connector from being plugged into the 24V control box connector. In fact keying won't prevent the sensor from being plugged into the wrong spot.



That's interesting stuff, but not applicable since (a) the system is not using XLR connectors (the connectors look very similar hence the picture but about 1/3 to 1/4 the size) and (b) keying won't help or prevent anything.

I said it "it looks like that connector". It is not that exact connector. It is not an XLR connector as shown tin the example picture. The connectors I am dealing with are only 1/4" in diameter, an XLR is about 3 times that large.

Don't know if you have enough room, but since the sensor only needs 1.5 ma. max why not just a 1k 1/2 w resistor in series with the 5/24 volts and a 5.1 volt zener to ground after it?