Rectifier diode

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DexterMccoy

Joined Feb 19, 2014
429
CR19 diode cuts off the negative cycle , leaving just a positive pulsing waveform?

Does it cut off the whole negative cycle or just limits the amplitude of the negative cycles? creating a Half wave waveform

Is CR19 a rectifier diode?

Because I thought a rectifier diodes was in series not in parallel
 

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Thread Starter

DexterMccoy

Joined Feb 19, 2014
429
CR18 only turns ON when the output of AR2 op amp LM101 output pin#6 is more or less Positive then R41 3K resistor tied to -10 volts?

When CR18 turns ON , Rinput R17 10K is in a gain ratio with R40 ( 1.3K )

R17 = Rin
R38 = R feedback

R17 = 10K
R38 = 4.99K
 

shortbus

Joined Sep 30, 2009
10,045
Schematics are much easier to read when right side up.
He is entitled to answers from the forum. He doesn't have time to arrange his attachments correctly before posting them. We're supposed to download and flip them for him! Everything he attaches is side ways, part of the game.
 

wmodavis

Joined Oct 23, 2010
739
When posing a question and/or solution or a proposal, clear, precise communication rises to the top of the list as to what gets helpful answers, comments or even consideration.
 

Thread Starter

DexterMccoy

Joined Feb 19, 2014
429
I think they call these types of diodes that are on the output a SHUNT NEGATIVE CLIPPER

But I don't know why they need to Shunt the negative cycle of the waveform on the Pitch Servo Sum output for the Pitch servo sums input
 

Thread Starter

DexterMccoy

Joined Feb 19, 2014
429
Why can transistor take a higher positive voltage then a negative voltage? Can a high large negative voltage damage the input stage of an op amp?
 

daviddeakin

Joined Aug 6, 2009
207
Why can transistor take a higher positive voltage then a negative voltage?
The base-emitter junction is a diode. Nothing more, nothing less. And like any diode, if you make the reverse voltage too large, it breaks down.
It doesn't really 'withstand' positive (forward) bias voltages; that's just its normal operating mode.

Can a high large negative voltage damage the input stage of an op amp?
Yes absolutely. Sometime you find a pair of diodes connected in anti-parallel between the inputs of an opamp, to prevent the voltage between the inputs from being too great. Opamps like to have their inputs at the same voltage; they don't like to have them pulled apart like a comparator (although FET opamps will withstand such differential voltages more than BJT opamps).
 

Thread Starter

DexterMccoy

Joined Feb 19, 2014
429
But when u have these clamping diodes only on the negative cycle voltage, it clips or shunts the negative cycle off which means the signal is a pulsing half wave form going to the input of a transistor or oop amp. Yes the diode protects it from a large negative voltage bbut it changes the waveform into a pulsing waveform
 
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