31,832
edits
155-0076-00: Difference between revisions
→Probe Readout Ring Decoder
| Line 19: | Line 19: | ||
consequently the darlington pair of Q69 and Q70 is turned on, | consequently the darlington pair of Q69 and Q70 is turned on, | ||
sinking current from the X1 pin of the M94. | sinking current from the X1 pin of the M94. | ||
[[File:Tek m94 probe ring decoder.png|600px|M94 Probe Ring Decoder]] | |||
When a 10x probe is connected, the voltage of the probe pin ring is determined by a voltage divider | |||
formed by the 5 kΩ resistor (to +5 V) in the scope and the 11 kΩ resistor (to ground) in the probe. | |||
The voltage at pin 11 of the M94 is 3.44 V. | |||
Q62 is off and Q63 is on. | |||
Current is allowed to flow out of the base of Q64, | |||
and Q65 and Q66 are on. | |||
The X10 pin of the M94 is sinking current. | |||
[[File:Tek m94 probe ring decoder 11k.png|600px]] | |||
==Used in== | ==Used in== | ||