Cam switches: Difference between revisions
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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. | ||
The original idea for the]is switch type is credited to [[Howard Vollum]] - see [[Patent US 3562464A|Patent 3,562,464 ''Cam actuated switch having movable and fixed contacts on circuit board'']] (Vollum, Verhoff, Sprando). | |||
[[Ken Holland]] was involved with the development of cam switches at Tek. | [[Ken Holland]] was involved with the development of cam switches at Tek. | ||
For cleaning, Tek recommends swiping paper soaked in isopropyl alcohol between the contacts and pads. | |||
==Maintenance== | ==Maintenance== | ||
* [ | * [[040-0541-00|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 | * [[Media:Tekscope 1977 V9 N1.pdf | TekScope Vol. 9 No. 1, 1977]] p.14: Cam switch cleaning tips | ||
* [[Media:Tek cam switch repair manual.pdf|Tektronix cam switch repair manual]] | * [[Media:Tek cam switch repair manual.pdf|Tektronix cam switch repair manual]] | ||
Revision as of 02:54, 27 March 2022
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.
The original idea for the]is switch type is credited to Howard Vollum - see Patent 3,562,464 Cam actuated switch having movable and fixed contacts on circuit board (Vollum, Verhoff, Sprando).
Ken Holland was involved with the development of cam switches at Tek.
For cleaning, Tek recommends swiping paper soaked in isopropyl alcohol between the contacts and pads.
Maintenance
- 040-0541-00 Cam switch repair kit (1970)
- TekScope Vol. 9 No. 1, 1977 p.14: Cam switch cleaning tips
- Tektronix cam switch repair manual
Pictures
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Cam switch in 7A19
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Cam switch in 7A19
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Cam switch in 7A19, contact fingers (isolated from spring lever)
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Cam switch with contacts on both sides of the PCB (7D15)
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7D15 double-sided switch
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7D15 double-sided switch
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7D15 double-sided switch, bottom-side contacts
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7D15 double-sided switch, through-board pins
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