In this picture can you ID the component that senses temperature? - Page 1
Forum section: electronics / testgear

author: alank2
author_rank: Super Contributor
timestamp: September 08, 2013, 10:47:00 pm
content: Hi,A rubidium module fits in the square cut out and part of this units management provides a rubidium temperature, but the rb module does not have an onboard temp, so I think it must be on this board. Probably in the upper left someplace - the picture zooms in quite a bit - can you identify which component senses the temp?http://www.ko4bb.com/Manuals/05%29_GPS_Timing/RFTG-m/RFTG-m-rb_L105A_Hi_res/lucent%283%29.jpgThanks,Alan

author: firehopper
author_rank: Frequent Contributor
timestamp: September 09, 2013, 03:36:36 am
content: Quote from: alank2 on September 08, 2013, 10:47:00 pmit could be almost any diode or resistor, but it may possibly in one of those metal cans as well

author: free_electron
author_rank: Super Contributor
timestamp: September 09, 2013, 06:33:17 am
content: It could be on board the microcontroller as well... Some cpus have built in temp sensors

author: ablacon64
author_rank: Frequent Contributor
timestamp: September 09, 2013, 11:42:21 am
content: As other pointed I don't know where the sensor is but something caught my attention: What is FL102 and FL103? Looks like a ceramic capacitor in a coil's enclosure....

author: Dago
author_rank: Frequent Contributor
timestamp: September 09, 2013, 12:40:17 pm
content: Quote from: ablacon64 on September 09, 2013, 11:42:21 amIt is an EMI suppression block by Murata:http://search.murata.co.jp/Ceramy/image/img/PDF/ENG/L0117BNX00.pdfApparently kind of like a ceramic cap with big ferrite beads in its "legs".

author: Orange
author_rank: Frequent Contributor
timestamp: September 09, 2013, 03:11:47 pm
content: Why do you expect a temp control on this board ?The rubidium module used in here is an Efratom LPRO-101. This is an autonomous module. It only needs a good thermal contact between the box chassis and the bottom side of the module.

author: alank2
author_rank: Super Contributor
timestamp: September 09, 2013, 03:45:50 pm
content: Quote from: Orange on September 09, 2013, 03:11:47 pmBecause I don't see any place in the LPRO interface where it can indicate its temperature. It is bolted to the floor of the RFTG which is basically a giant heat sink. The board above sits around it. The temperature the management software indicates is higher than my sensor and suggests the area of the LPRO where the Rb physics package is near. I wonder if the temperature is pulled into the board via the single pcb mount in the upper left and something on board is used to sense it.I've attached a sensor to the other side of the LPRO (where the interface port is) because I made a small aluminum adapter that lets me press a TO92 sensor up to the LPRO case. The management software shows 48.5141 C, but I've got a PID control loop running an AVR that varies a fan RPM in an attempt to keep the LPRO stable temp wise. So far it is working well and has been keeping the temp at 40 deg C +/- 0.15 C.I'm just curious is someone could recognize the where on the pcb the temp might be being sensed.Thanks,Alan

author: ablacon64
author_rank: Frequent Contributor
timestamp: September 09, 2013, 11:02:20 pm
content: Quote from: Dago on September 09, 2013, 12:40:17 pmThanks!