cap-inductor-pulse charge (CIP-Charge)
Well I asked myself that same crazy question ... see.
Here's what happens when you discharge a Capacitor into an Inductor:
Perhaps this is another way to crack open the local field and have a drink for free.
I conducted an experiment on a hunch. I took a capacitor and charged it. Then I dumped it into an inductor. There is a 'first' large negative-going oscillation that is captured by a diode and charges a second capacitor.
Here's the set-up:
First the test circuit here:
http://02d1852.netsolhost.com/radian...st_circuit.jpg
on the left side is the common or ground. connected to the 'common' are V-, scope probe gnd, one end of the inductor and one side of three capacitors. The upper orange cap is the cap that gets charged up and dumped to the inductor. The yellow cap is the cap that gets charged through the 1N4001 diode. The red alligator clip is connected to the post (bent cap lead) and the other end of the alligator clip's wire is momentarily switched to V+ to charge the orange cap and then switched to the inductor to complete the cycle. The lower orange cap is a control. It's used as a reference to compare the differences in the waveforms between the upper charge circuit and the raw cap to inductor circuit with no second cap & diode.
The waveform for a straight up cap discharge into an inductor here:
http://02d1852.netsolhost.com/radian...o_inductor.jpg
scale's on the picture at 3V x 1ms.
The waveform of the yellow cap being charged by the 'first' negative-going oscillation here:
http://02d1852.netsolhost.com/radian...tor_to_cap.jpg
Probe load can be a problem when measuring small energies like I was. With both scope probes on the orange and yellow caps, the signal gets strangle pretty bad. But I wanted to post them both. First the hook-up and then the waveform:
http://02d1852.netsolhost.com/radian...two_probes.jpg
and now the probe loaded waveform here:
http://02d1852.netsolhost.com/radian...probe_load.jpg
An indirect way around this was to try and get a look at how the charging cap voltage tracks the inductor's oscillation ... hopefully with a parallel track at a diode-drop distance ... and it does. The waveform shows this here:
http://02d1852.netsolhost.com/radian...diode_drop.jpg
The waveforms are indeed separated by the 'measured' 0.514V drop of the 1N4001.
So now we know it tracks the oscillation perfectly so we can use this in our energy calculation without having a probe on the charging cap (yellow) to distort the results.
You can see the entire set-up here:
http://02d1852.netsolhost.com/radian...lse/set_up.jpg
The inductor is the primary of a 24VAC step-down transformer. It measures 10.2 Ohms. The secondary and center tap are left open.
Switching was manual and I simply had a tinned wire that I switched back and forth between V+ (red clip) and the other end of the inductor (chrome clip). An image of that is here:
http://02d1852.netsolhost.com/radian...harge_dump.jpg
Here' the shocker: The cap that smacks the inductor is 0.047uF and the cap that gets charged from the inductor's oscillation is 1.0uF. See them here:
http://02d1852.netsolhost.com/radian...pulse/caps.jpg
So how much energy is coming from the 0.047uF 'dump' cap (orange) into the inductor, and how much energy is being harvested from the local field by the inductor to charge the charging cap (yellow)?
1/2 CV^2 = joules:C = capacitance, V = voltage, joules = ...well, "joules"
looking at:
http://02d1852.netsolhost.com/radian...tor_to_cap.jpg
in the 'dump' cap we see 10.5 VDC.
(10.5^2 / 2) x .047 / 1000000 = 2.590875 x 10^(-6) joules
in the charge cap we see (-)2.9VDC.
2.9 - .514 (don't forget the diode drop!) = 2.386
(2.386^2 / 2) x 1.0 / 1000000 = 2.846498 x 10^(-6) joules
WHAT ? ... OUTPUT TO INPUT RATIO = ?
2.846498 / 2.59087 = 1.0986 ... ALMOST 110% ... COP = 1.1
Well this isn't far off. This is an interesting experiment to say the least. Next time I'll tie all outputs to OP Amp Buffers to side step the probe load problem.
set-up for just the cap to inductor reference here:
http://02d1852.netsolhost.com/radian...p_inductor.jpg
for the first (raw) waveform above again here:
http://02d1852.netsolhost.com/radian...o_inductor.jpg
Probably need a separate thread for this,
Greg
Originally posted by gmeast
View Post
Here's what happens when you discharge a Capacitor into an Inductor:
Perhaps this is another way to crack open the local field and have a drink for free.
I conducted an experiment on a hunch. I took a capacitor and charged it. Then I dumped it into an inductor. There is a 'first' large negative-going oscillation that is captured by a diode and charges a second capacitor.
Here's the set-up:
First the test circuit here:
http://02d1852.netsolhost.com/radian...st_circuit.jpg
on the left side is the common or ground. connected to the 'common' are V-, scope probe gnd, one end of the inductor and one side of three capacitors. The upper orange cap is the cap that gets charged up and dumped to the inductor. The yellow cap is the cap that gets charged through the 1N4001 diode. The red alligator clip is connected to the post (bent cap lead) and the other end of the alligator clip's wire is momentarily switched to V+ to charge the orange cap and then switched to the inductor to complete the cycle. The lower orange cap is a control. It's used as a reference to compare the differences in the waveforms between the upper charge circuit and the raw cap to inductor circuit with no second cap & diode.
The waveform for a straight up cap discharge into an inductor here:
http://02d1852.netsolhost.com/radian...o_inductor.jpg
scale's on the picture at 3V x 1ms.
The waveform of the yellow cap being charged by the 'first' negative-going oscillation here:
http://02d1852.netsolhost.com/radian...tor_to_cap.jpg
Probe load can be a problem when measuring small energies like I was. With both scope probes on the orange and yellow caps, the signal gets strangle pretty bad. But I wanted to post them both. First the hook-up and then the waveform:
http://02d1852.netsolhost.com/radian...two_probes.jpg
and now the probe loaded waveform here:
http://02d1852.netsolhost.com/radian...probe_load.jpg
An indirect way around this was to try and get a look at how the charging cap voltage tracks the inductor's oscillation ... hopefully with a parallel track at a diode-drop distance ... and it does. The waveform shows this here:
http://02d1852.netsolhost.com/radian...diode_drop.jpg
The waveforms are indeed separated by the 'measured' 0.514V drop of the 1N4001.
So now we know it tracks the oscillation perfectly so we can use this in our energy calculation without having a probe on the charging cap (yellow) to distort the results.
You can see the entire set-up here:
http://02d1852.netsolhost.com/radian...lse/set_up.jpg
The inductor is the primary of a 24VAC step-down transformer. It measures 10.2 Ohms. The secondary and center tap are left open.
Switching was manual and I simply had a tinned wire that I switched back and forth between V+ (red clip) and the other end of the inductor (chrome clip). An image of that is here:
http://02d1852.netsolhost.com/radian...harge_dump.jpg
Here' the shocker: The cap that smacks the inductor is 0.047uF and the cap that gets charged from the inductor's oscillation is 1.0uF. See them here:
http://02d1852.netsolhost.com/radian...pulse/caps.jpg
So how much energy is coming from the 0.047uF 'dump' cap (orange) into the inductor, and how much energy is being harvested from the local field by the inductor to charge the charging cap (yellow)?
1/2 CV^2 = joules:C = capacitance, V = voltage, joules = ...well, "joules"
looking at:
http://02d1852.netsolhost.com/radian...tor_to_cap.jpg
in the 'dump' cap we see 10.5 VDC.
(10.5^2 / 2) x .047 / 1000000 = 2.590875 x 10^(-6) joules
in the charge cap we see (-)2.9VDC.
2.9 - .514 (don't forget the diode drop!) = 2.386
(2.386^2 / 2) x 1.0 / 1000000 = 2.846498 x 10^(-6) joules
WHAT ? ... OUTPUT TO INPUT RATIO = ?
2.846498 / 2.59087 = 1.0986 ... ALMOST 110% ... COP = 1.1
Well this isn't far off. This is an interesting experiment to say the least. Next time I'll tie all outputs to OP Amp Buffers to side step the probe load problem.
set-up for just the cap to inductor reference here:
http://02d1852.netsolhost.com/radian...p_inductor.jpg
for the first (raw) waveform above again here:
http://02d1852.netsolhost.com/radian...o_inductor.jpg
Probably need a separate thread for this,
Greg
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