Misc Electronic Questions

[Billy Mayo]

The solid state relay is powered by 120 volts AC , the signal of the solid state relay goes direct a controller PIN

What does the solid state relay do?



Op-Amp Detector, What does it do ?



Here is an RC network in the feedback section of an op-amp , what does it do?



This IC voltage Detector, goes direct to the Micro-controllers RESET pin, what does the IC voltage detector do? once the VCC is to low it Resets the Micro-controller?

If there is a short and the VCC is low all the time , it's just going to keep Resetting the Microcontroller right?



What does these LF13333N Switches do?

When they have an square waveform on the input pin of a LF13333N the output of the LF13333N switch changes the Amplitude of the square waveform i have noticed




What does the Diodes do? The Nor gates have these Diodes for what?

 

[KeepItSimpleStupid]

I=V/R. As R gets smaller, I gets bigger.

The other problem is that the power supply has some sort of current limiting.

One method is this: https://en.wikipedia.org/wiki/Foldback_(power_supply_design)

 

[audioguru]

If the resistance of a short is only 0.5 ohms and causes the 5V supply to drop to 2V then using Ohm's law: 2V/0.5 ohms= 4A or 4000mA.

 

[Billy Mayo]

If the resistance of a short is only 0.5 ohms and causes the 5V supply to drop to 2V then using Ohm's law: 2V/0.5 ohms= 4A or 4000mA.

Yes true

I just don't get the water analogy of how a low water level can have very Big or large water Flow or pressure

Current = water flow or water pressure rate

how can you have a small tank of water that's water level is 1/16 inch and have the water flowing at a very fast speed that can cause damage

SHORT = Very low voltage , VERY high current = IC chips gets HOT

SHORT= Very low water level, VERY fast water flowing, Won't break a water pipe or put out a fire

 

[Billy Mayo]

There is a lot of waveforms when I'm probing around on circuit boards at work that are very hard to trigger it seems with the oscilloscope

They keep "free running" even at any setting on my trigger on the oscilloscope

I even change the volts/per knob and adjust the trigger level and I still can't get the waveform to sit still , its keeps "free running" , I might be able to slow it down some , but it keeps Free running

The Trigger mode is on channel#1 , Trigger is in Auto mode

What Can I do? and why won't these waveforms trigger? are they to fast or what?

 

[Billy Mayo]

What does those peak detector op amps do for digital TTL or CMOS logic signals? what are the peak detector op amps used for?

 

[KeepItSimpleStupid]

Don't use auto-trigger. Use the level/slope controls or external triggering off of a related signal.

PS: Did you read your PM?

 

[Billy Mayo]

Don't use auto-trigger. Use the level/slope controls or external triggering off of a related signal.

I do use the level slope controls and the waveform is still in free running , I can't get it to stop

I'm not sure why these waveforms I can't seem to stop, are they to fast?

 

[KeepItSimpleStupid]

I asked earlier about an instruction manual. Some scope have difficulty triggering on channel #1 just based on the scope design.

If you have many periods of the waveform visible, it's usually more difficult to trigger on it as well.

 

[Billy Mayo]

Yes it does help when I only have one or 2 periods when triggering thanks

 

[Billy Mayo]

1.) The Diodes are for when the NOR gate is in the OFF state
When the NOR gate is in the ON state is a time constants from the capacitor and resistor and when the OFF state is doesn't go through the resistor, is goes through the diode

2.) The Diodes protect it from creating a short circuit since the NOR gates are connected in Parallel





This is a comparator op-amp
When a Logic HIGH is on the input , the output is a LOW
When a logic LOW is on the input, the output is a HIGH
The Diode is to set the hysteresis



I'm not sure when they didn't use a Schmitt invertor instead

I guess the diode sets up a DC offset voltage?

 

[Norator]

I get the feeling you're in over your head.

In your situation I'd find ways to independently confirm what the people at work tell you. People may observe things correctly but drawing correct conclusions about 'why?' is more difficult and sometimes they come up with the most outlandish ideas.
This confirmation process also helps when troubleshooting so that you don't go very far off on the wrong path.

Here's a thought experiment for you.
There is a wire coming out of a box in a very old house wall. It is insulated but the color has been painted over.
How to tell if it goes to a neutral, a ground, a hot lead or one side of some kind of load?
How to tell if the connections back to the panel have integrity?
What test instruments do you need? Why these in particular?

Another question:
What is more likely to correctly predict LED brightness, LED current or LED voltage? How do you know? What is your reasoning?

BTW, some people you work with may be there because they have merit and others may be 'political appointees' in the broadest sense.
Avoid the second group if you can identify them - they are probably incompetent and almost certainly proud, both at the same time, and they can get you fired for cause or without cause.

And if there is ever a circuit problem and someone says "It's a ground loop" ask them for a diagram showing where the current goes. Expect a lot of hand waving at this point.

 

[Billy Mayo]

I posted the wrong pictures he is the right one

This is a comparator op-amp
When a Logic HIGH is on the input , the output is a LOW
When a logic LOW is on the input, the output is a HIGH
The Diode is to set the hysteresis

 

[Billy Mayo]

What do the 2 resistors do? the ones I circled, I see these a lot in logic circuits, It's not just a voltage divider, its like it's pull up the logic signal to a reference zero

Does the 2 resistors level shift the logic signal?

Does the 2 resistor Clamp the Logic signal to clip at a certain voltage?

Why is the VCC +5 and the VDD - 15 volts? why not -5 volts or zero volts, why -15 volts?

Click here:

 

[audioguru]

Your schematics are useless because they do not have a DOT where a wire joins another wire.

 

[Billy Mayo]

Yes true, The Designer at my work didn't put in the junction nodes

But What can you make out of it from my questions please would help me out a lot

 

[Billy Mayo]

The High state is +5 volts and the low state is -15 volts, why not zero volts? why is it -15 volts?

 

[KeepItSimpleStupid]

Why is the VCC +5 and the VDD - 15 volts? why not -5 volts or zero volts, why -15 volts?

I'll bet that +5 is a common logic level and a Vdd of -15 is available.

Op amps have LOTS of trouble with voltages at their supply rails. Only recent OP amps are doing a good job at it. Older OP amps/comparators can only swing within say 1.2 V of a power supply rail.

 

[Billy Mayo]

Op amps have LOTS of trouble with voltages at their supply rails.

What u mean by this? trouble in what way?

Older OP amps/comparators can only swing within say 1.2 V of a power supply rail.

1.2 Volts Positive and negative only 1.2 volts in either direction?

 

[KeepItSimpleStupid]

OK, I'll pick a random popular device, the LM334: https://www.electro-tech-online.com/custompdfs/2013/04/lm124-n-1.pdf

Note that with a +15V supply, the large signal swing is 1 to 11V. You don't always get the supply rails.