hi hgmjr.
well i am back to show you what i am doing. but first things first.
i managed to blow all my HE switches ( no surprise there). luck for me i have some OPB 876 optic transistors laying about, so i have had to connect up a new circuit as you see in the picture. if you would be a gentle man again and help me on my new circuit.
the second picture is off my disk ( a very nice job, if i may say so myself, in making it) the primary coil is small but should give a good kick. i have placed 4 AIR coils on the out side of the disk gauge 24.
i have got the 4 coils connected and then through a full bridge recifier.
i am getting out 9.50 volts DC at 75 RPM.
i get 18 volts spinning the disk as fast as i can with my finger. i know that it can go much faster and make alot more power.
so how about it! together we can make this work. i can buy most parts needs if another circuit need to be build.
i was thinking about using a IR emitter and IR detector as the sensor, which would be the best one.
if need be a 741 op amp circuit, all ideas are welcome
amps

 

hi hgmjr.
well i am back to show you what i am doing. but first things first.
i managed to blow all my HE switches ( no surprise there). luck for me i have some OPB 876 optic transistors laying about, so i have had to connect up a new circuit as you see in the picture. if you would be a gentle man again and help me on my new circuit.
the second picture is off my disk ( a very nice job, if i may say so myself, in making it) the primary coil is small but should give a good kick. i have placed 4 AIR coils on the out side of the disk gauge 24.
i have got the 4 coils connected and then through a full bridge recifier.
i am getting out 9.50 volts DC at 75 RPM.
i get 18 volts spinning the disk as fast as i can with my finger. i know that it can go much faster and make alot more power.
so how about it! together we can make this work. i can buy most parts needs if another circuit need to be build.
i was thinking about using a IR emitter and IR detector as the sensor, which would be the best one.
if need be a 741 op amp circuit, all ideas are welcome
amps

OK jasonspinmaster,

I just noticed you are back and ready to pick up where we left off.

Sorry to here about the demise of the HE sensors. Do you know what happened to damage them?

hgmjr

 

hi there
i will start from the top the new circuit is connected i am getting from the output of the sensor i am getting 13.65 volts with the sensor open i get 0.65 volts when is is bloked
from the base of the small transistor i get 0.78 volts with the sensor is unbloked and 0.60 volts when the sensor is bloked

 

hi there
i will start from the top the new circuit is connected i am getting from the output of the sensor i am getting 13.65 volts with the sensor open i get 0.65 volts when is is bloked
from the base of the small transistor i get 0.78 volts with the sensor is unbloked and 0.60 volts when the sensor is bloked

That would mean that the BC548 is not going to turn off.

What are the blocked and unblocked voltages at the collector of the BC548?

hgmjr

 

the collector volt when it is unbloked is 0.03 volts and blocked is 0.92 volts

 

Is the circuit generating the pulses you need?

hgmjr

 

i am getting a pulse but not saturating the power transistor.
the transistor seems to switch on but slowly to by the time it gets to about 75 rpm it seem like it whats to go faster but can not.
how can i which on the transistor faster, would it be an idea to put in the circuit an ops amp???

 

You may want to try decreasing the 4.7K resistor in the collector of the BC548 from 4.7K to 2.2K again. That may give you the base drive you need.

hgmjr

 

i have change the 4.7k fromthe collector to a 2.2k resistor, but still does not give the kick it needs
i asked about the op amp as i found this circuit on the web

 

As an experiment, can you temporarily replace the load on the power transistor with a resistor the value of which is equal to the DC resistance of your coil?

This will let you see the output signal from the power transistor more clearly without the inductance effect.

hgmjr

 

my coil resistance is 03.6 ohms i do not have that low aresistor

 

In the interest of keeping the power dissipation reasonable, do you have a 100 ohm resistor? Preferrably one that is rated for at least a couple of watts.

hgmjr

 

no i do not have that resistor i will have to go to the shops and buy one, but here in spain the shops reopen at 5pm in an hour

 

You can put something together by paralleling say five 470 ohm resistors as a work around.

hgmjr

 

i do not have any 470 resistor so i will have to go shopping. the shop is only 10 minutes away.

 

i have just connected another coil with thinker wire an air coil but the disk spinns much faster.
i have a question. i am using a 12 volts battery, and just now i got 25 volts DC out of the 4 x coils, is that right, if it is can iput the 25 volts back into the circuit as to run itself????

 

i have just connected another coil with thinker wire an air coil but the disk spinns much faster.
i have a question. i am using a 12 volts battery, and just now i got 25 volts DC out of the 4 x coils, is that right, if it is can iput the 25 volts back into the circuit as to run itself????

I don't know enough about your overall system design to comment on your observation of a higher voltage.

Sadly, conservation of energy dictates that you cannot get more energy out than you have put in.

If you can provide a more comprehensive schematic showing the overall system I should be able to identify why you are seeing the higher voltage. Most likely you are seeing the flyback voltage that results from switching the drive to your relay or coil. These higher voltages are accompanied by lower currents so that power is conserved.

At this point, what is it about the performance of the design you need to improve upon.

hgmjr

 

the 25 volts that i made comes from a seperate part of the circuit.
the circuit for the trigger and coil is not connectedto the 4 x coils
i need to gett the trigger circuit working. i am going to go back and try a few new coils

 

hi hgmjr,
i have made a video of the circuit but i can not post it, but i have an other question if i may
where would i place a variable resistor to control the speed off the motor???

 

where would i place a variable resistor to control the speed off the motor???

Are you proposing to put a resistance in line with the power to the motor and control the speed by adjusting the resistance?

hgmjr