RadioBanter - View Single Post - Connectin a TO-92 hall effect sensor to wires

February 15th 04, 07:43 PM

In article ,
(tim) writes:

What is the best way to attach a hall effect sensor in a TO-92 package
to 22 gauge solid wire?

Soldering.

I've tried just laying the wire next to the
to-92 lead and soldering them together, but I don't get much of a
mechanical connection doing that.

Good soldering technique forms a very strong intermetallic bond
by itself. Tektronix proved that in production of their first
oscilloscopes, just laying in wires to terminal posts instead of
wrapping them first.

Is there some type of sleeve I should be using prior to the soldering?

Teflon prior to soldering. PVC sleeve after soldering. Either.
Your choice.

I would suggest #24 or #26 gauge wire, maybe a tweezer-like
heat sink to avoid too much heat into the TO-92 plastic case
through the leads.

Also, any suggestion on encapulating the device once the electrical
connections are made?

Any two-part epoxy having a filler...making it "thick" or viscous.
That will bond nicely to the epoxy TO-92 case.

I've made a temperature probe out of a 2N3877 in a TO-92 many
years ago using #24 stranded. Leads soldered in-line with the
transistor leads. Thick epoxy over the leads. Diameter was no
larger than the TO-92 largest diameter. PVC sleeving slipped over
the soldered joints after soldering...I think...epoxy covered it up. :-)

The only problem was the overall mass of the probe as a
temperature measuring device...got replaced with a welded
thermocouple about a decade after fabrication in 1968. Still works
for temping large masses. Hall effect is for magnetic fields and the
method is non-magnetic unless there is a strange epoxy with a
metal powder filler.

Len Anderson
retired (from regular hours) electronic engineer person