Help me find a replacement relay - Page 1
Forum section: electronics / general

author: asp
author_rank: Regular Contributor
timestamp: March 20, 2014, 07:20:46 pm
content: Hi guysI wanted to ask you if you know of any relay that can replace the Agilent pn "0490-1914" it is a RELAY-REED 2A,5VDC COIL either Coto 3200-0121 or Meder BT05-BV50324 but I am unable to find any at a reasonable price that would deliver to UK.Does anyone know of a replacement relay for that? I also looked at Coto 3540 that I think is the replacement part but can't find that part either ( unless I order 300 of them ).ThanksPS: I just need 1

author: asp
author_rank: Regular Contributor
timestamp: March 22, 2014, 09:04:48 pm
content: I still can't find any so unless anyone comes up with some amazing stuff I think I will just use a random relay that might do the job ( I can't even find a relay that's pin compatible

author: SArepairman
author_rank: Frequent Contributor
timestamp: March 22, 2014, 09:42:06 pm
content: I always wanted a trained mouse for range switching O0you can pay the mouse in food to flip switches.

author: XOIIO
author_rank: Super Contributor
timestamp: March 22, 2014, 09:44:59 pm
content: ebay has a bunch of listings though no pictures of the relayhttp://www.ebay.ca/sch/i.html?_trksid=p2050601.m570.l1313&_nkw=Coto+3200-0121&_sacat=0&_from=R40edit: crap, those must be lots or something due to the shipping amount.Can you upload some pictures of it? I don't have any reed relays but might have some with similar pins.

author: XOIIO
author_rank: Super Contributor
timestamp: March 22, 2014, 09:46:47 pm
content: Quote from: SArepairman on March 22, 2014, 09:42:06 pmI want to see a switch mode power supply done like that.

author: asp
author_rank: Regular Contributor
timestamp: March 23, 2014, 06:22:56 pm
content: Quote from: XOIIO on March 22, 2014, 09:44:59 pmI will take some photos tomorrow morning and upload them. And will double check the size if it's compatible with a Coto 3540-05 ( for that I found a datasheet ) and if everything turns out fine I found out thishttp://www.onlinecomponents.com/coto-technology-354005911.html?p=11192792and for 20$ they seem to get it in 12 weeks. But anyway I will get some pictures tomorrow morning and some distances between pins

author: asp
author_rank: Regular Contributor
timestamp: March 23, 2014, 08:24:16 pm
content: Ok found this picture of a HP 34401 teardown on the forum and you can see the relay there ( the red-orange can labeled 0490-1914 / Coto-0214)

author: XOIIO
author_rank: Super Contributor
timestamp: March 23, 2014, 08:44:13 pm
content: Quote from: asp on March 23, 2014, 08:24:16 pmI'm almost completely sure I have some of those, I just need to find the container in the mess of a room I have right now.

author: XOIIO
author_rank: Super Contributor
timestamp: March 23, 2014, 09:01:10 pm
content: I knew I had one! I salvaged it from some UPS or something. It's not identical to the one on the picture, but maybe it's specs will match yours. (or it will be a suitable substitute, it does still work.)edit: whoops, rotated the image.

author: asp
author_rank: Regular Contributor
timestamp: March 24, 2014, 07:32:29 am
content: Thanks for the reply but that's not the correct relay. I attached a photo of the relay with it's widths and height and pin spacing/

author: KSP
author_rank: Regular Contributor
timestamp: March 24, 2014, 09:36:34 am
content: HelloI am on the case as well. I have a HP34401A DMM which needs the same relay replaced. Agilent want £35.68 for it, which seems excessive as I see this fault a lot and I would like to buy a job lot of them... Boss man will not sign an order for 100x £35.68!!! Even getting one at that price will p*ss him off...But the trouble is even if you buy a different relay and attempt to mod the unit it seems that most, if not all, high current relays are about the same price (using RS/Farnell as reference). All relays with a max switching current of >= 2A seem to be around the £30 mark, so maybe this is just the way it has to be. For once it looks like Agilent are actually selling them at roughly market price, as opposed to their usual 500% mark up! (so I may be exaggerating slightly, but their prices are usually high...)But still, if someone does find a suitably priced alternative please do share!P.s. Hello everyone, I just joined this forum for the sake of this postbut I intend to stay!

author: andtfoot
author_rank: Unknown
timestamp: March 24, 2014, 11:26:19 am
content: Is it possibly the same as the HP part number 0490-1914?After a quick search to that effect, I found a couple of hits. It might be worthing firing off a question to the suppliers to check if it's one and the same.http://www.onlinecomponents.com/hewlett-packard-04901954.html?p=11508461http://www.lintechcomponents.com/product/5945-013963010http://www.parttarget.com/5945-01-396-3010_5945013963010_0490-1914.html/-B187965D-259A-46B0-8B0E-C6F7731A5F53I've never heard of the suppliers in the links, so I have no idea if they are good, bodgy, existing, etc...

author: KSP
author_rank: Regular Contributor
timestamp: March 24, 2014, 01:22:04 pm
content: Yeah it is the same relay. The three part numbers I have for it are 0490-1914 (HP/Agilent number), 3200-0121 (COTO number) and BT05-BV50324 (MEDER ELECTRONIC number), but like you say I dont recognise those websites either. I may send some emails to try and get quotes, as the cheaper price may be redundant when you add the cost of shipping to the UK. But who knows, may get luckyEdit: I checked the postage costs of the first link you posted and its an ample $50... The price of the relay varies from $10.32 to $11.97 depending on the quantity bought, so cost savings can be achieved here! (Exchange rate taken into consideration and all that)But whether they are trustworthy or not I dont know, I usually only buy from the big names

author: HighVoltage
author_rank: Super Contributor
timestamp: December 29, 2015, 12:39:38 pm
content: I was also looking for this very same relay for an Agilent 34410A instrument and was not successful in obtaining one. Will just order an original from Keysight.Here is a picture of the relay, that is inside the 34410A.May be someone coming across this thread can point to an obtainable alternative.In that case, thanks for posting...

author: TimFox
author_rank: Super Contributor
timestamp: December 30, 2015, 06:18:46 pm
content: Not directly relevant to your particular relay, but a heads-up when you replace it:I have an -hp- 8013B pulse generator that uses a reed relay to switch in the 50-ohm back-termination resistor (the pulse source has a current output).The operation was erratic, so I replaced the relay. The original relay company had been sold to Coto, and the device was still available. Coto p/n 8L01-05-011 (5 V DC coil, 1A = SPST NO contact).Most of these relays have the internal diode option, which makes the coil polarity-sensitive. Somehow, the relay had been installed backwards (rotated 180 deg), so the connections were correct except for the diode polarity. There were no signs of previous repair on the PCB, so it must have slipped through -hp-'s outgoing tests. With the very low coil voltage (clamped by the diode), the reedalmostworked.If you replace a reed relay, make sure the orientation gives correct coil polarity.

author: HighVoltage
author_rank: Super Contributor
timestamp: December 30, 2015, 07:13:05 pm
content: Interesting, thanks for the info.The diode is probably just a flyback diode to kill back voltage from the coil in your case?I opened my relay today but did not see any diode inside.https://www.eevblog.com/forum/repair/agilent-34410a-repair-attempt-of-2-dead-meters/msg832114/#msg832114Also, in my case the footprint is different and the relay can not be flipped 180 degree.

author: TimFox
author_rank: Super Contributor
timestamp: December 31, 2015, 03:07:17 pm
content: Yes, it is a flyback diode. You should be able to see if it is installed with an ohmmeter: asymmetric values with opposite polarity.

author: w9sz
author_rank: Newbie
timestamp: July 20, 2020, 05:32:46 pm
content: If anyone is still looking for a replacement for this, this is an almost drop-in replacement: COTO 3501-05-511https://www.mouser.com/ProductDetail/Coto-Technology/3501-05-511?qs=%2Fha2pyFadugZH48hv7vzIOHC%2FiNqsHn8TZEIql2XBVw%3DThe one I received had an extra not-connected pin between the two pins on the relay coil end, which I cut off