Cam switches: Difference between revisions

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Cam switches are used in many Tek instruments, particularly in [[7000-series plug-ins]], but also in 400-series portable scopes.
Cam switches are used in many Tek instruments, particularly in [[7000-series plug-ins]], but also in [[TM500]] equipment and 400-series portable scopes.


The lobes on the rotary cam encode the lookup table of which contacts should be open or closed in each rotational position of the shaft,
The lobes on the rotary cam encode the lookup table of which contacts should be open or closed in each rotational position of the shaft,
which is typically rotated by a knob on the front panel of the instrument.
which is typically rotated by a knob on the front panel of the instrument.
A benefit of this design is low parasitics compared to traditional rotary wafer switches.
A benefit of this design is low parasitics compared to traditional rotary wafer switches.
For cleaning, Tek recommends swiping paper soaked in isopropyl alcohol between the contacts and pads.


==Maintenance==
==Maintenance==
* [http://hakanh.com/dl/docs/kitinstructions/040-0541-00.pdf 040-0541-00: Cam switch repair kit (1970)]
* [http://hakanh.com/dl/docs/kitinstructions/040-0541-00.pdf 040-0541-00: Cam switch repair kit (1970)]
* [[Media:Tekscope 1977 V9 N1.pdf | TekScope Vol. 9 No. 1, 1977]] p.14: Cam switch cleaning tips


==Pictures==
==Pictures==
<gallery>
<gallery>
Tek 7a19 frontright.jpg|Cam switch in [[7A19]]
Tek 7a19 frontright.jpg | Cam switch in [[7A19]]
Tek 7a19 rearright.jpg|Cam switch in [[7A19]]
Tek 7a19 rearright.jpg | Cam switch in [[7A19]]
Tek 7a19 att sw3.jpg|Cam switch in [[7A19]], contact fingers
Tek 7a19 att sw3.jpg | Cam switch in [[7A19]], contact fingers (isolated from spring lever)
Cam-01.jpg
Cam-01.jpg | Cam switch with contacts on both sides of the PCB ([[7D15]])
Cam-02.jpg
Cam-02.jpg | 7D15 double-sided switch
Cam-03.jpg
Cam-03.jpg | 7D15 double-sided switch
Cam-04.jpg | 7D15 double-sided switch, bottom-side contacts
Cam-05.jpg | 7D15 double-sided switch, through-board pins
Tek cam switch cam.jpg
</gallery>
</gallery>


[[Category:Repair issues]]
[[Category:Repair issues]]
[[Category:Electromechanical components]]

Revision as of 17:16, 12 May 2017

Cam switches are used in many Tek instruments, particularly in 7000-series plug-ins, but also in TM500 equipment and 400-series portable scopes.

The lobes on the rotary cam encode the lookup table of which contacts should be open or closed in each rotational position of the shaft, which is typically rotated by a knob on the front panel of the instrument. A benefit of this design is low parasitics compared to traditional rotary wafer switches.

For cleaning, Tek recommends swiping paper soaked in isopropyl alcohol between the contacts and pads.

Maintenance

Pictures