Back EMF Volts Available From Inductors Circuit??

Thread Starter

russwr

Joined Aug 29, 2017
35
How can I get minimum 100v back emf from Inductor coils using these values? 20v DC, 7amp, with 2 inductors each .0015 Henry that has diode in series in between. (.003H) Shut off Time about .029second. based on duty cycle applied included? Possible? Or different shut off time?? Is this also positive Back EMF as was the input volts? Doesn't the VOLTAGE increase because of coil higher volts enters SECOND coil , so as even higher volts available? To make use of this forward Back EMF, should I use half wave DC rather than full wave DC, so that there is an OFF time available for the higher volts to be able to go forward? Full wave DC has no spacing in between pulses. This circuit was used in Georgia about 2008 with pulsing 38v half wave DC, and no one was able to figure it out , about how it got at least 100v out, superimposed on the input.
 

crutschow

Joined Mar 14, 2008
34,016
You description is rather confusing and does not make good sense (such as the diodes in between the inductors).
Please post a circuit schematic as Alec requested.
 

Papabravo

Joined Feb 24, 2006
20,990
Used in Georgia in 2008 for what? By who?
I do not think the Georgia being referred to is the State of Georgia in the USA, but rather the small country in the Caucasus Mountains between the Black and the Caspian Seas, bordering Russia, Türkiye, Armenia, and Azerbaijan.
 

MrAl

Joined Jun 17, 2014
11,256
How can I get minimum 100v back emf from Inductor coils using these values? 20v DC, 7amp, with 2 inductors each .0015 Henry that has diode in series in between. (.003H) Shut off Time about .029second. based on duty cycle applied included? Possible? Or different shut off time?? Is this also positive Back EMF as was the input volts? Doesn't the VOLTAGE increase because of coil higher volts enters SECOND coil , so as even higher volts available? To make use of this forward Back EMF, should I use half wave DC rather than full wave DC, so that there is an OFF time available for the higher volts to be able to go forward? Full wave DC has no spacing in between pulses. This circuit was used in Georgia about 2008 with pulsing 38v half wave DC, and no one was able to figure it out , about how it got at least 100v out, superimposed on the input.
Hi,

When you energize an inductor and then disconnect it, you always get a very high voltage across the inductor for a short time.
If you need accurate control though there will be other parts involved.

The usual way to do this it to connect one end of an inductor to the positive supply +Vcc, then the other terminal to the collector of an NPN transistor. When the transistor turns on it energizes the inductor, and when it turns off the voltage at the collector shoots very high. That is also how a boost converter is done. In your case though you may need to control it a little different.

What is the application for this?
 

WBahn

Joined Mar 31, 2012
29,844
Were you really expecting an answer? I think you may be disappointed.
Neither expectation nor disappointment enter into it. The question gets answered or it doesn't. If it gets answered, we may be in a better position to provide assistance. Maybe not. If it doesn't, then that possibility is taken off the table. That simple.
 

MisterBill2

Joined Jan 23, 2018
17,763
"used in Georgia", probably by "A Rambling Wreck From Georgia Tech", for purposes that could not be recalled the following morning. Probably it was in a switch-mode power supply delivering in excess of 140% efficiency. The design details could not be recalled the following morning, it seems. So additional research is required, along with much more legible design notes.
UNtil then, no claims for being able to build a model or even reproduce the design.
 
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