how can i test an SCR in a servo control circuit with only a DVM and O'scope.475 volts,1/2 wave ,60 AMP 4 quad
371756
Assuming that you are not removing the SCR from the circuit.\nTry to look at the gate signal and the output at the cathode on a double beam 'scope while the servo is trying to operate. Or disconnect the gate and try to turn the SCR on from an external source and see if you get output motion from the servo or whatever the output is.Some caution required with 440 v !!Some recollection from 25 yrs ago may help ? Making a bridge  or H-switch to drive a 1/2 hp dc motor. Collected a pile of dud transistors on bench until able to prevent simultaneous turn-on down one side of the bridge. This is prevented by correct commutation and ensuring that during switching, the instantaneous power dissipation in the device remains outside the specified region.Commutation is aided by placing an air-core inductor in series with the load and then usng a secondary winding on this to make sure that when one side is conducting that the other arms are turned off.It is somewhat tricky and very critical.
317786
http://www.electrospec.com/electronic/components-parts/index350.html\n\ntry here!!
289376
wow an 8051. I wish i could help but it has been more than 10 years since i did anything with something like that.\n\nGood luck.
1086026
You can get an idea on counting the discs on the insulator string and multiplying by 12kV/disc.\nAgain it is only a general rule of thumb and is not accurate.\n\nSource 50 years as an Electrical Engineer
532709
the minimum current needed to cause the thyristor to latch/switch state
595239
Typing "short circuit program" into Google or Yahoo produces the following sites selling programs designed to calculate fault currents for power systems.\n\nhttp://www.bussmann.com/apen/software/s_circuit.asp\nhttp://www.elitesoft.com/web/electrical/elite_short_info.html\nhttp://www.easypower.com/short_circuit.html\nhttp://www.cai-engr.com/sc.htm\nhttp://www.durandassociates.com/Short_Circuit/short_circuit.html\n\nTake your pick...
712713
Generally, in the CROs i hav used there is a knob near the bottom in which the output wires can be put to check you are getting some form of wave.. then the CRO is working.. if u dont get the exact output wave, then check with the probes, circuit...
1058406
At my job, I maintain lager equipment and small equipment for Land O’ Frost. We have motor that we use variable frequency drives on. The VFD’s range from 480VAC 3 phases to 24VAC single phase on the input side to 1000VDC, 480 single phases, 120VAC on the output side. But when installing a VFD the thing that are considered before installing one are the size of the motor 5hp, 35hp, .25hp, how many amps are needed to run the motor and peak amps so the parts are not over current. The voltage is another thing, the amount of programming that you can do so you can set limits for everything. It can take a long time to find what you need. Have fun shopping
870052
Full example and circuit diagram on http://www.padre.ca/house/multiplier_example_web.pdf
183707
Follow the bottom 2 links that I am going to post to get a labeled schematics\n\nhttp://www.kids-online.net/learn/click/details/sblvalpci.jpg\n\nhttp://dmzweb4.europe.creative.com/wwimages/audio_int/sblive/liveplayerconnect600.gif
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I sense that you have no clue what you're doing. Tell me I'm wrong.\n\nFor DC circuits, Ohm's law says: V = I * R, voltage equals current times resistance.\n\nYour circuit will consist of a battery (voltage source) and a load (resistance) plus the wires to connect them and the meter(s).\n\nIdeally you will test one battery at a time. That way the load will be identical (including the small resistance of the wires).\n\nBatteries typically have two ratings: voltage and capacity.\nVoltage is measured in volts and this decreases as the battery discharges. Capacity is measured in amp hours (current multiplied by time) which specifies how long the battery can deliver a current.\n\nAssuming the circuit resistance is constant (reasonable assumption for your purposes), when you connect the battery to the load, the voltage (independent variable) will cause a current (dependent variable) to flow. As the battery discharges, the voltage will decrease, and the current will correspondingly decrease. You will need a watch or timer as well. Time zero will be when you first connect the battery. Measure the battery voltage at that instant and at intervals. Depending on the load and how fast the battery discharges should determine how frequently you take measurements.\n\nmsg me when you have the data if you need help analyzing it.
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Quite simple really. All you need is a photodiode detector sensitive in the infrared region and a computer or oscilloscope to measure the voltage difference of your photodiode detector.\n\nYour homebrew device is useful, but only as useful as the components it is constructed of. Lab quality devices cost tens of thousands of dollars and have well conditioned electronics.
1169979
Figure 8 in the following link shows an open loop test circuit
1177496
If you have a voltage regulator that is poorly designed (or adjusted?) it will overshoot the target voltage then correct and overshoot in the other direction, etc. etc.  Usually there must be some type of feedback in the circuit that accepts small deviations rather than "hunt" for a too precise voltage value.  Hope that helps a little.
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If it's for a simple hobbyist application they need to know only the resistance value and its power rating.\n\nA full specification would also include:\n\ntolerance,  thermal coefficient,  maximum voltage.
704421
Either an "open or short" circuit
888482
Please contact your local professional service centre.  \nDo not scratch your head with V= I X R.\nIf you still want to do your self,  use single phase varioc.  \nvoltage from 0. \nNormally Fridge comes with 230 volts input in India, \nrest of the world, I don't know.