Using a Hall sensor

[JulesP]

Hi John,

That sounds like an ideal solution. Did you use that in 'attraction' mode where the 'on' time finished just before TDC? Do you have a circuit diagram for that and is it straightforward to integrate it into my circuit which is shown as image 'BEMF Circuit 2' at: https://www.dropbox.com/sh/0y15dybr5...mn2q6QhHCa?dl= 0

Thanks

Jules

[energialibre]

Gracias por su sugerencia. Como entiendo que el modo 'Atracción' es más eficiente, ¿puedo usar o modificar el circuito que ha demostrado que se ejecuta en ese modo? Como mi circuito es un derivado de los circuitos tipo Bedini y no un SG, y también solo usa una batería (que se muestra en la imagen 'BEMF Circuit 2' en: https://www.dropbox.com/sh/0y15dybr5...mn2q6QhHCa?dl= 0) ¿Puedo
lograr eso con solo un sensor Hall?

Amigo recuerda que si la salida del sensor hall es mayor de 4 o 5 voltios pon una resistencia en la base del transistor para que no se queme. Hay sensores hall variables que le puedes aplicar desde 3 voltios a 24 voltios pero la salida del sensor hall tambien varia y puede ser de 50 voltios a si que ten cuidado de no quemar el transistor y ponle la resistencia en la base. El circuito que te pasado es un circuito basico que sirve de aprendizaje para comprender como funcionan los motores electricos. Se le pueden hacer muchas modificaciones al circuito. Un abrazo

[John_Koorn]

Hi John,

That sounds like an ideal solution. Did you use that in 'attraction' mode where the 'on' time finished just before TDC? Do you have a circuit diagram for that and is it straightforward to integrate it into my circuit which is shown as image 'BEMF Circuit 2' at: https://www.dropbox.com/sh/0y15dybr5...mn2q6QhHCa?dl= 0

Thanks

Jules

Hi Jules, sorry I don't have a schematic for it - it was a long time ago and I'm not sure where I saved it. Should be pretty simple though, it's a pretty standard Monostable 555 circuit. From memory the output of the 555 triggered an opto-coupler, which in turn controlled the trigger transistor.

John K.

[John_Koorn]

Hall Triggered FET Bedini SSG

Hi Jules,

I was going through some old files today and found this one. I hope you find it useful

John K.

Hall Triggered FET Bedini SSG.pdf

[John_Koorn]

Trigger Coil FET SSG

Hi Jules,

Here's a trigger coil version I built. I recall that the trigger coil was a separate single wound coil that was mounted in between the motor coils.

John K.

Trigger Coil FET SSG.pdf

[JulesP]

John thanks for that,

I can see the Hall sensor on the left, then the power transistor and then 5 FETs. Am I right in thinking that this design doesn't use the opto trigger you mentioned? was that for another circuit? Also can this circuit be adpated to run with one battery and at 12V rather than the 24V in your diagram?

Regards,

Jules

[John_Koorn]

John thanks for that,

I can see the Hall sensor on the left, then the power transistor and then 5 FETs. Am I right in thinking that this design doesn't use the opto trigger you mentioned? was that for another circuit? Also can this circuit be adpated to run with one battery and at 12V rather than the 24V in your diagram?

Regards,

Jules

Hi Jules,

Yes, the opto trigger was a different circuit - sorry for the confusion.

No, the hall circuit (as well as the inductive trigger one) can't be adapted to run with one battery - it's a two battery system. I used 24V because you I needed the 15V from the 7815 on the gate of the FET to fire it.

I guess if you wanted to run at 12v you could adapt it with a DC-DC converter to get the required gate voltage, but IMO much easier to just run it at 24V as per the schematic.

John K.

[Gary Hammond]

Hi Jules,

Here is the schematic of a circuit I developed to trigger my 5 transistor SSG using two hall sensors triggered by the same south pole magnet. The two halls can be placed closer or farther apart to change the pulse width and can also be adjusted together to change the timing. Both halls need to conduct at the same time to trigger the rest of the circuitry.

This machine is running in attraction mode. The coils pulse a south pole toward the wheel and the magnets on the wheel have the north poles outward toward the coils. Triggering is from the back side of the magnets (south poles) a few degrees before the magnets reach the edge of the coil cores. It will run in only one direction.



I also have a hall switched FET circuit driving my switched reluctance attraction motor. It uses a single hall in a circuit similar the the one above. The FET replaces the transistor in an SSG type circuit. (I'm on vacation for a couple more days and don't have access to that circuit at the moment but will post it after I get back home.) Here's a video of it running.

Most hall switches are triggered by facing toward a south pole, not a north pole. Some can be triggered by facing the hall switch away from the north pole but not as reliably. I don't know if this is how the South African inventor did it, or if he reversed all the magnets in the rotor and then reversed all the coil windings. In order for switching to take place when the magnet is centered over the coil core, it has to be running in repulsion mode.

Are you sure that all your coils have the same polarity, and the north pole is facing the rotor? You can momentarily apply 12 volts across the coils and see if the rotor is pushed away or pulled in when the rotor is slightly out of alignment with the coils.

Also, the single battery circuit you proposed won't work to recharge the battery, as the diodes produce a short circuit directly across the coils the way you have it drawn. If you want to run with a single battery, you can by going back to powering the circuit with an dc to dc convertor (or inverter/transformer/rectifier/filter). That way you can drop the coil discharges directly across the battery like the circuit shown in this link. http://www.free-energy-info.com/Chap...e-fit,-312,842

[Gary Hammond]

Hi Jules,

Hi Jules,
.....................................I also have a hall switched FET circuit driving my switched reluctance attraction motor. It uses a single hall in a circuit similar the the one above. The FET replaces the transistor in an SSG type circuit. (I'm on vacation for a couple more days and don't have access to that circuit at the moment but will post it after I get back home.) ..................................

Here's a hand drawn schematic of the circuit for my "Rotary Attraction Motor" that I posted back on 4-20-17 http://www.energyscienceforum.com/sh...ll=1#post26610. I started out with an MJL21194 transistor which was overheating, and then I just replaced it with an IRFP4310Z FET in the same circuit which now runs cool to the touch. The gate to ground resistor should probably be increased from 220 ohms to 2200 ohms to provide a higher voltage gate signal to the FET. I used a 2N4919 transistor to drive the FET.

[JulesP]

Gary, Ive been trying to reply to you for days but all I get is: www.energyscienceforum.com is currently unable to handle this request.
HTTP ERROR 500

What does this mean?!

[JulesP]

Hi Jules,

Here is the schematic of a circuit I developed to trigger my 5 transistor SSG using two hall sensors triggered by the same south pole magnet. The two halls can be placed closer or farther apart to change the pulse width and can also be adjusted together to change the timing. Both halls need to conduct at the same time to trigger the rest of the circuitry.

This machine is running in attraction mode. The coils pulse a south pole toward the wheel and the magnets on the wheel have the north poles outward toward the coils. Triggering is from the back side of the magnets (south poles) a few degrees before the magnets reach the edge of the coil cores. It will run in only one direction.



I also have a hall switched FET circuit driving my switched reluctance attraction motor. It uses a single hall in a circuit similar the the one above. The FET replaces the transistor in an SSG type circuit. (I'm on vacation for a couple more days and don't have access to that circuit at the moment but will post it after I get back home.) Here's a video of it running.

Most hall switches are triggered by facing toward a south pole, not a north pole. Some can be triggered by facing the hall switch away from the north pole but not as reliably. I don't know if this is how the South African inventor did it, or if he reversed all the magnets in the rotor and then reversed all the coil windings. In order for switching to take place when the magnet is centered over the coil core, it has to be running in repulsion mode.

Are you sure that all your coils have the same polarity, and the north pole is facing the rotor? You can momentarily apply 12 volts across the coils and see if the rotor is pushed away or pulled in when the rotor is slightly out of alignment with the coils.

Also, the single battery circuit you proposed won't work to recharge the battery, as the diodes produce a short circuit directly across the coils the way you have it drawn. If you want to run with a single battery, you can by going back to powering the circuit with an dc to dc convertor (or inverter/transformer/rectifier/filter). That way you can drop the coil discharges directly across the battery like the circuit shown in this link. http://www.free-energy-info.com/Chap...e-fit,-312,842

Hi Gary (9th attempt),

Thank you for the comprehensive response.

I am using a A3144E Hall sensor that, after being unable to get them to trigger with my North pole outward facing rotor magnets, I discovered are designed to trigger with a North pole on one side and a South pole on the other so I simply flipped it and the connection wiring over and it triggers fine. Trouble is, as I say in my early posts, they come on maybe 10 degrees before TDC and off again about 10 degrees after TDC and which will not allow either repulsion or attraction mode to work without some more elaborate timing and pulse width facility.

I note you say that your design needed both Halls to switch on at the same time. Surely the one closest to the approaching magnet will come on first or is the time difference too small to affect the circuit? It would be good to see a photo of their physical arrangement in situ as I presume you must be able to adjust their spacing and position finely enough to effect millisecond adjustment? One query here though; whatever timing and duration you setup, won't that only be correct for only one specific rotor rpm? As the rotor starts from near zero rpm the pulse width would be longer at the start and decrease with increasing rpm. John Koorn spoke of an optical sensor and a slit in a disc that made it independent of rpm but I haven't seen any specifics of the circuit or physical setup.

As you say I do need to confirm that my coils are all creating a South pole facing the rotor magnets. Based on my observation of the cogging when the coil currents are on (and my FET is getting really hot!) that is so but I will check each one individually.

I will confer with the developer re the diodes shorting the output to the battery. I still can't quite see how that's happening and the path the short is taking?

I hope you are enjoying your hols

Jules

[Gary Hammond]

Hi Jules,

Gary, Ive been trying to reply to you for days but all I get is: www.energyscienceforum.com is currently unable to handle this request.
HTTP ERROR 500

What does this mean?!

I've never gotten that error on this web site, but I sometimes get it on another web site that I regularly visit. I think that happens when one of the servers in the data communication path goes down. I don't know how many servers there are between England and the western US, but I suspect there are many!

[Gary Hammond]

Hi Jules,

Hi Gary (9th attempt), ...................................I note you say that your design needed both Halls to switch on at the same time. Surely the one closest to the approaching magnet will come on first or is the time difference too small to affect the circuit? It would be good to see a photo of their physical arrangement in situ as I presume you must be able to adjust their spacing and position finely enough to effect millisecond adjustment? One query here though; whatever timing and duration you setup, won't that only be correct for only one specific rotor rpm? As the rotor starts from near zero rpm the pulse width would be longer at the start and decrease with increasing rpm. John Koorn spoke of an optical sensor and a slit in a disc that made it independent of rpm but I haven't seen any specifics of the circuit or physical setup. .............

Each Hall and associated circuit is mounted on separate perf boards that are individually, mechanically adjustable, but electrically connected in series. Each board is mounted on the interior of the wheel next to the south face of the magnets. One on each side (right and left) of the wheel. Both halls are triggered by the same magnet each time, but one is slightly ahead of the other which shortens the distance both are on at the same time. This allows for changing the % of on time (duty cycle) to get the best spike with the least current. By moving both boards in the same direction, at the same time, the timing can be adjusted as well. The duty cycle and degrees of timing advance stay the same regardless of rpm, just like an optical sensor would. Here's a couple of photos of the setup.

As you say I do need to confirm that my coils are all creating a South pole facing the rotor magnets. Based on my observation of the cogging when the coil currents are on (and my FET is getting really hot!) that is so but I will check each one individually.

If you have the coils south poles facing the magnets north poles, it's running in attraction mode and must have advanced timing. If the polarity of the coils and magnets are the same, it will run in repulsion mode (south to south OR north to north) and must be triggered on at top dead center. (I have mine running in attraction mode.)

As for the short circuit I was talking about, what you show is the diodes completing a circuit path directly back to the opposite end of the coils on discharge and bypassing the battery. The coil reverses polarity, becoming a high voltage source (rather than a voltage sink) when the current is abruptly stopped. I copied your schematic and hand drew the current path to show the short circuit.

[JulesP]

Coil Discharges

Hi Gary,

I think I have figured out why you say that my HV coil discharges will be shorted. In the US you use 'electron flow' nomenclature for your components and we use 'conventional current'. Those three diodes should be reversed then from your POV so that when the bottom of the coils become positive electron flow can't occur as you indicated in the drawing.

[Gary Hammond]

Hi Jules,

Hi Gary,

I think I have figured out why you say that my HV coil discharges will be shorted. In the US you use 'electron flow' nomenclature for your components and we use 'conventional current'. Those three diodes should be reversed then from your POV so that when the bottom of the coils become positive electron flow can't occur as you indicated in the drawing.

[ATTACH=CONFIG]7089[/ATTACH]

No. We use "conventional current" for our schematic symbols as well. (I usually think in terms of "electron current" because that's how I was originally taught.) The diodes are shown in the correct direction in the schematic.

What you are overlooking is the polarity reversal of the coils when the magnet field collapses. When the FET stops the current flow, the magnetic field collapse cutting across the coil windings tries to keep the current flowing in the same direction. (Inductive impedance always resists a change in the rate of current flow.) Now the coils become the voltage source at whatever voltage it takes to find a path with the top of the coils now being the negative end and the bottom of the coils becoming the positive end. So the coils now cause a high voltage "spike" of "conventional current flow" to travel from the bottom of the coils (momentary positive end), around the top loop in the schematic, thru the diodes, and back to the top of the coils (momentary negative end). This is the short circuit. The coils are directly shorted out by the diodes.

There is no path back thru the battery to charge it from the high voltage spike. There may be some radiant get back to the battery (as in the original school girl motor), but not enough to keep it charged and self running. Most of the coil discharge energy is going to be expended in the diodes creating heat. If you scope the coils, the voltage spikes will be very small with the circuit configured this way.