creating a new part

torsdag den 26. august 2021 kl. 21.40.49 UTC+2 skrev John Larkin:

and a half twist only works on connectors that connect on both top and bottom (at the risk of connecting it wrong), or with a cable that has connections on both side (at the risk of connecting it wrong) or on top at one end and bottom at the other end

This info really belongs on the Assembly level, not on the part.

Cheers

torsdag den 26. august 2021 kl. 23.47.45 UTC+2 skrev Martin Riddle:

sure, but would be nice with a reminder that if you want to use a straight standard single sided cable it'll swap

Oh, right. Our connectors are one-sided. I'll just have to swap the pin numbers on the ends.

This is bringing three temperature sensors (each a thermistor Wheatstone bridge) out of my monster aluminum block oven, through a narrow slot machined into 0.5" thick aluminum. It's great that no connectors need to pass through the slot.

I have a Spice model of the thermistor bridge if anyone is interested.

Watch out for the monster heat leak, if you're using the standard Molex rolled-wire FFCs. Flex circuit is your friend for that job, ideally half ounce Cu or thinner, with narrow traces.

Sure, I'd be interested in the model--we use a lot of thermistors.

Cheers

Phil Hobbs

On Fri, 27 Aug 2021 09:01:58 -0400, Phil Hobbs snipped-for-privacy@electrooptical.net wrote:

I'll be using the 1 mm pcb stuff. I plan to measure the electrical resistance which inferrs the thermal resistance.

Version 4 SHEET 1 1164 680 WIRE -224 -144 -416 -144 WIRE 16 -144 -224 -144 WIRE -224 -64 -224 -144 WIRE 16 -64 16 -144 WIRE 240 0 176 0 WIRE 288 0 240 0 WIRE 176 48 176 0 WIRE 16 64 16 16 WIRE 128 64 16 64 WIRE -608 112 -656 112 WIRE -560 112 -608 112 WIRE -224 112 -224 16 WIRE 128 112 -224 112 WIRE -656 176 -656 112 WIRE -416 176 -416 -144 WIRE -224 176 -224 112 WIRE 16 176 16 64 WIRE 176 176 176 128 WIRE -656 320 -656 256 WIRE -416 320 -416 256 WIRE -224 320 -224 256 WIRE 16 320 16 256 FLAG -416 320 0 FLAG -224 320 0 FLAG -656 320 0 FLAG -608 112 TC FLAG 240 0 Vtemp FLAG 16 320 0 FLAG 176 176 0 SYMBOL res -240 160 R0 WINDOW 0 57 53 Left 2 WINDOW 3 -152 209 Left 2 SYMATTR InstName R1 SYMATTR Value R={R25*exp(B*(1/(V(TC)+TK)-1/(T25+TK)))} SYMBOL voltage -656 160 R0 WINDOW 0 23 137 Left 2 WINDOW 3 -52 199 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value PULSE(25 45 0 20 0 1k) SYMBOL voltage -416 160 R0 WINDOW 0 65 38 Left 2 WINDOW 3 59 71 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName Vref SYMATTR Value 2.500 SYMBOL res -208 32 R180 WINDOW 0 -67 69 Left 2 WINDOW 3 -70 34 Left 2 SYMATTR InstName R2 SYMATTR Value 10k SYMBOL res 0 -80 R0 WINDOW 0 -64 43 Left 2 WINDOW 3 -393 480 Left 2 SYMATTR InstName R3 SYMATTR Value R={R25*exp(B*(1/(V(TC)+TK)-1/(T25+TK)))} SYMBOL res 32 272 R180 WINDOW 0 64 59 Left 2 WINDOW 3 58 30 Left 2 SYMATTR InstName R4 SYMATTR Value 10k SYMBOL e 176 32 R0 WINDOW 0 58 54 Left 2 WINDOW 3 63 83 Left 2 SYMATTR InstName E1 SYMATTR Value 1 TEXT 128 312 Left 2 !.param R25=15k\n.param B=3950\n.param Tk=273.15\n.param T25=25 TEXT 168 256 Left 2 !.tran 20 TEXT -696 -96 Left 2 ;T500 Thermistor Bridge TEXT -672 -40 Left 2 ;MAX # 194-0005 TEXT -664 16 Left 2 ;JL Aug 26 2021 TEXT -632 144 Left 2 ;sweep 25-45 C TEXT 160 -80 Left 2 ;50 mV / degC TEXT 160 -112 Left 2 ;0 at ~35 degC TEXT -72 0 Left 2 ;thrm TEXT -192 240 Left 2 ;thrm TEXT -376 272 Left 2 ;ADR421A TEXT 200 24 Left 2 ;ADS1246 TEXT -192 32 Left 2 ;Susumu TEXT -80 272 Left 2 ;Susumu

Any of the rolled-wire type such as this one

is likely to present problems.

For connecting to cold plates we really like the Molex 502598-xx93 series, which correspond to their 15015-xxxx jumpers. They're 0.3 mm pitch, copper on Kapton, but the connectors fan out into two rows of 0.6 mm pitch so they don't short out as easily if you put them in a little crooked. (0.5 mm FFCs tend to do that.)

Yup. Thermistors rock for narrow range stuff.

Cheers

Phil Hobbs