Mercury switches: Difference between revisions

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Mercury switches were used in several Tektronix products  
'''Mercury switches''' were used in several Tektronix products for generating pulses with clean edges.   
for generating pulses with clean edges.   
 
The switches are electromagnetic relays with mercury-wetted contacts
The switches are electromagnetic relays with mercury-wetted contacts inside glass envelopes that contain pressurized gas.   
inside glass envelopes that contain pressurized gas.  The gas prevents
The gas prevents arcing of the contacts. In some models, a physically adjustable bias magnet (permanent) is used to "bias" the reed switch in its normally closed position.
arcing of the contacts. Mercury switches have limited life.   
Mercury switches have limited life.   
In pulse generators, the coil of the relay is typically driven by a  
 
multivibrator or other periodic current source.  
In pulse generators, the coil of the relay is typically driven by a multivibrator or other periodic current source.  
Turning off the coil drive waveform when the pulse generator is not in use
Turning off the coil drive waveform when the pulse generator is not in use is recommended.
is recommended.


Tektronix products using mercury switches are:
Tektronix products using mercury switches are:
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* [[S]] (part# 260-308)
* [[S]] (part# 260-308)


==Pictures==
<gallery>
<gallery>
Image:Tek 108 mercury switch.png|108 Mercury switch
Image:Tek 108 mercury switch.png|108 Mercury switch
Tek_260-0282-02_1.jpeg | 260-0282-02 From type [[84]]
Tek_260-0282-02_2.jpeg | 260-0282-02 From type [[84]]
Tek_260-0282-02_3.jpeg | 260-0282-02 Disassembled - reed switch, bias magnet, driving coil & mounting hardware
Tek_260-0282-02_4.jpeg | 260-0282-02 Mercury-wetted reed switch
</gallery>
</gallery>


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

Latest revision as of 23:16, 2 January 2021

Mercury switches were used in several Tektronix products for generating pulses with clean edges.

The switches are electromagnetic relays with mercury-wetted contacts inside glass envelopes that contain pressurized gas. The gas prevents arcing of the contacts. In some models, a physically adjustable bias magnet (permanent) is used to "bias" the reed switch in its normally closed position. Mercury switches have limited life.

In pulse generators, the coil of the relay is typically driven by a multivibrator or other periodic current source. Turning off the coil drive waveform when the pulse generator is not in use is recommended.

Tektronix products using mercury switches are:

  • 108 (part# 260-194)
  • 109, 84 / 067-0523-00 (part# 260-0282-02)
  • 110 (part# 260-334)
  • P (part# 050-106 for sn up to 2396, 260-539 after)
  • R (part# 260-250)
  • S (part# 260-308)

Pictures