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    Diode on Pin1 and Pin8 on Opamp, does what?

    What does this diode do on pin#1 and Pin#8 on this Op-amp? Mostly I see a capacitor on Pin#1 and Pin#8 for frequency compensation Are they using the capacitance of the diode? Take a look please
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    back to back zener diodes does what?

    What does these back to back zener diodes do? Why are the reverse polarity back to back?
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    Comparators with diodes on the output why?

    I don't understand why there is diodes on the output of these comparators? any reason Is it about sinking and sourcing current? Because a comparator with switch from a low state to a high state, so the diode does what?
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    Test Fixture patch bay Diodes?

    On test fixtures , they have a patch bays that has multiple jacks on the front panel What does these diodes do? the diodes are in series If you plug the wrong jacks together, how does these diodes protect the text fixture? If a tech injected a Positive voltage into a jack , how would a...
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    Transistors switch on output pin or input pin

    What does these transistors do? U2 , 2N2920 They are placed on the op amps output pin and another transistor is placed on the input of an op amp It seems that these transistors are used as switches to clean up or switch off so the output pin of a op amps is not leaky noise or voltage when...
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    What kind of relay is this?

    What kind of relay type is this? What tool would you guys use to get them out of the sockets When I used pilers, it squeezed the chassis of the relay and smashed it There is too many components around the relays to get a flat head screw driver underneath it, it lift it out
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    Measuring 800hz ripple looks like noise

    Measuring 800hz ripple from a power supply looks like noise I didn't know the output of a power supplies noise was ripple, I thought ripple was a sawtooth looking waveform 60hz ripple looks like a sawtooth waveform 400hz and 800hz ripple looks like noise When measuring Ripple: I'm using...
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    Measuring the Low state of TTL, CMOS , Pulses

    How do you measure the Low states voltage on TTL, CMOS or pulse waveforms? I have read that the Low states voltage can range from -2 volts vdc to + 2 volts vdc What would cause the Low state to go to -2 volts vdc? or to +2 volt vdc? I'm using a Tektonrix TDS 2022 I go to the Horizontal...
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    Calculating gain in this op amp stage

    The input voltage is 8.8 vdc going to R117 U12 pin#6 output voltage is 4.4 vdc How do you calculate the gain? What does C38 do? What kind of gain stage is this called? it's weird how they arranged Rin and the feedback RF Plus the signal and voltage is going to both inputs , so it's some kind...
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    Input impedance and Max RMS ac voltage

    Bench Equipment have different input and output impedance and Max RMS voltage 50 ohms = Max 5 volts RMS 75 ohms = Max 10 volts RMS 1K ohm = Max 15 volts RMS 1 Meg ohm = Max 20 volts RMS How did you get the RMS voltage? without knowing the current? What happens when you put a higher AC voltage...
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    DVM meter capacitance mode has internal battery?

    When using a DVM meter to measure capacitors In Capacitance mode there is an internal battery and a Diode? What is the diode used for and how does the diode get damaged? The internal battery needs to be changed, but the internal battery is only used for measuring capacitors Fluke 87
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    Universal Counter is not stable with a load why?

    I use these Universal counters HP5315B Universal Counter HP5334B Universal Counter I'm using a Ling Function generator for a waveform generator Sine waveform at low frequencies I use the Universal counter to display a digital readout of what the frequency is of the sine waveform When I...
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    Meg ohm resistors , are opens circuits?

    When looking at a schematic that has Meg ohm resistors in series, is this like an open circuit when a resistor in the meg ohms is in series or in parallel? Why would you want to use resistors in Meg ohms in series? I have seen resistors in Meg ohms in parallel for impedances of the inputs or...
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    Negative Trigger mode on O-scope used for?

    When do you use the Negative trigger mode on the O-scope? and what is the negative triggering used for? When I'm measuring TTL or CMOS Logic signals, the positive or negative trigger gives me the same result, doesn't change anything. The pulse width, time period, time duration's all have the...
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    IH5011 Fet switch , virtual ground switch?

    IH5011 FET switch, virtual ground switch it says on the datasheets How is it a virtual ground switch? When the FET is ON or OFF the diode is always in a parallel circuit which causes current to bleed and sink take a look at the hand drawings and schematic
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    In rush chokes on op amp inputs

    How does this chokes work when there is an in rush current? Does the chokes/coils delay the in rush current? the chokes/coils soak up and drain the in rush current? to protect the inputs of the op amps from getting damaged? What other purpose does these chokes/coils and capacitor on the input...
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    Positive and Negative regulators sections are different

    I don't understand what Q21 , 2N6315 on the Voutput pin#6 is going for the Positive +15 volts supply supply What is VR2, Q19, Q20 doing for the Negative supply on Voutput pin#6 ? what kind of circuit is V2, Q19, Q20? and why doesn't the positive regulator not have a VR2 or Q19, Q20 only the...
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    Complementary amplifier Differential Measurements for duty cycle

    Using an O-scope to measure Differential Measurements on Two channels for Complementary amplifiers. O-scope channel#1 is on the Positive cycle of the complementary amplifiers output O-scope Channel#2 is on the Negative cycle of the complementary amplifier output The input signal is not a...
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