RESONANCE EFFECTS FOR EVERYONE TO SHARE

[gotoluc]

Hi everyone,

I just uploaded a new video

I ask for your input to help solve what I maybe missing in my way of measurement in this test as I seem to be able to charge a 12,000uf cap bank (with 10 ohm load attached) to 3.12vdc in one second and cannot measure any current draw to achieve this

Video: http://www.youtube.com/watch?v=ETZaMrnIwxk

Thanks for your time.

Luc

[gotoluc]

To anyone interested,

changes have been made to Groundloop's circuit. I have updated it on the page I first posted it: http://www.overunity.com/index.php?topic=6225.msg142894#msg142894  but I am also including it here.

Changes that have been made to the circuit are, connection pins of the 4013 flip flop, the diodes have been upgraded to an Ultra Fast, some extra caps added to the IR212103 and also a 220uf cap added at entry and the resistors have been changed from 10 ohm to 50 ohm in order to help keep the IR2103 cooler.

Thanks Groundloop for your continuous help

Luc

[TinselKoala]

GNch.

Oh well. I just completed 90 percent of construction based on the "old" diagram. I might be able to get in there and rewire the 4013...

But the only driver chips I could find locally are the IR 2104, which is basically the same as the 2103 but the second input is an "inhibit". Shouldn't pose a problem as the chip should behave the same in this circuit. BUT:  I could only find it in the SOT package!! So another evening of tiny precision soldering to adapt them to DIP...

Thanks, groundloop and gotoluc!! This will be a very handy circuit for all kinds of things.

I wonder if one should insert a diode and/or capacitor in the input feed from the signal generator, to protect the 4013 inputs...?? And perhaps a current-limiting resistor and a fuse in the DC input line to protect the MOSFETs??

[gotoluc]

GNch.

Oh well. I just completed 90 percent of construction based on the "old" diagram. I might be able to get in there and rewire the 4013...

But the only driver chips I could find locally are the IR 2104, which is basically the same as the 2103 but the second input is an "inhibit". Shouldn't pose a problem as the chip should behave the same in this circuit. BUT:  I could only find it in the SOT package!! So another evening of tiny precision soldering to adapt them to DIP...

Thanks, groundloop and gotoluc!! This will be a very handy circuit for all kinds of things.

I wonder if one should insert a diode and/or capacitor in the input feed from the signal generator, to protect the 4013 inputs...?? And perhaps a current-limiting resistor and a fuse in the DC input line to protect the MOSFETs??

Hi TinselKoala,

sorry for the changes. I had mine built 100% and had to make all the changes, which also took 2 days of back and forth emails and attachments of scope shots to Groundloop in order to solve some of the arising problems. Much of the basic trouble shooting has been done but we can continue to develop as we go.

The IR2104 should be fine ... your soldering iron better have a fine tip with a SOT ... they should of called them SOB

Not a bad idea to add some protection.

I also think this circuit would have many uses ... thanks for all your help Groundloop.

Luc

[TinselKoala]

Whoo--whoo!

groundloop's and gotoluc's H-bridge rocks hard!

I must be getting lucky in my old age, because I built it, and it worked properly THE FIRST TIME!

I didn't rewire the 4013, although the new wiring would have been easier to route.
I used the IR 2104, which I only had in SOT, so I carefully soldered them to machine-pin 8 pin DIP sockets (using magnifiers and a tiny pointed tip on the Hako). This chip has an inhibit function that turns off all output MOSFETs, instead of the inverting input on the 2103. It turns out to be a good thing! I wired the inhibit pins to a toggle switch, so I can now easily turn off all 4 mosfets without disturbing anything else.
I made some little sockets for the MOSFET pins out of DIP header sockets (since I want to be able to change MOSFETs easily).
I'm still using 1n4007s. The fancy diodes come in tomorrow. Had to buy 15, though. Used the 50 ohm gate resistors.
I put in a few more 0.1 mfd decoupling caps, and LEDs on the output to show polarity.

Performance is impressive. I did some quick tests using an 11.4 v LiPo battery as the logic power and the pulse power. Clocked with the Interstate F34 (note: your clock must be able to supply at least 10 v p-p to trigger the 4013). The output pulses are nice and square and symmetrical. I hooked it up to my LTLOT solenoid as a load, and drove it from less than 1 Hz to over 300 kHz, monitoring on scope. At the higher freqs there's a little distortion and inductive ringing (what do you expect? I used the "rat's nest" wiring layout method) but I noticed no false triggering or bad behaviour.

The LTLOT solenoid really launches the sliding magnets with this setup. The bridge supplied enough current to almost melt down my plastic tube and bobbin in just a few tens of seconds of running. Nice to have that inhibit switch! I suppose I should measure the current, maybe put a fuse in.
The MOSFETs stayed cool throughout.

I'll post a picture of the thing in a few minutes.

THANKS, groundloop and gotoluc!

I recommend this bridge circuit.