Electret antenna out of an coaxial cable?

[Nink]

using pulsed-power signals to run those motors has had a lot of success in lowering power requirements per lift force.
increasing the runtime for the copters and gyros
as it turns out, pulsing the motor doesn't change the momentum a whole lot, so you still maintain a stable lift/wind force.
but run the motor at the same rpm, using a lower/shorter duty cycle.

Interesting, drone flight times are a real problem.  I have a low end quad that only gets ~ 7 minutes and a high end phantom with a 4480 mAh battery that only gets ~20 minutes.  Has anyone built a pulse motor drone?

[Magluvin]

using pulsed-power signals to run those motors has had a lot of success in lowering power requirements per lift force.
increasing the runtime for the copters and gyros
as it turns out, pulsing the motor doesn't change the momentum a whole lot, so you still maintain a stable lift/wind force.
but run the motor at the same rpm, using a lower/shorter duty cycle.

Hmm.  So are drone motors not pwm typically?

What you wrote maybe hit something on the head for me.

My electric bike hub motor is pwm till full throttle then is just putting battery to the windings with timing, looking at it with a scope. I had found that when I back off of the throttle some it has a bit more go. 

I mentioned this in Lucs sharing thread also.   Been thinking on ways to separate the windings of these multi phase motors so the windings are not connected to each other and have their own drive circuits. The reason being it is impossible to collect bemf from the windings when they are all connected. So in a way treat the drive coils like an inductor of a switching supply where we have electrical output from the circuit while still driving the motor.

Mags

[sm0ky2]

Hmm.  So are drone motors not pwm typically?

What you wrote maybe hit something on the head for me.

My electric bike hub motor is pwm till full throttle then is just putting battery to the windings with timing, looking at it with a scope. I had found that when I back off of the throttle some it has a bit more go. 

I mentioned this in Lucs sharing thread also.   Been thinking on ways to separate the windings of these multi phase motors so the windings are not connected to each other and have their own drive circuits. The reason being it is impossible to collect bemf from the windings when they are all connected. So in a way treat the drive coils like an inductor of a switching supply where we have electrical output from the circuit while still driving the motor.

Mags

I guess it depends on what type of bike motor you have.
the two types I have seen are a simple DC motor circuit, with a variable resistance.
and another with a stepper motor controlled by the throttle.

I guess you can say the same with the drones, but the more complex you get, the more likely
they would have implemented stepper motors. controlled by a logic circuit.
like a quad-copter

by pulsing the power or having an "off time" added to the duty-cycle
you decrease the power over time
if this can be done in a manner which does not allow the rotor to significantly slow down
then the overall energy to maintain the desired RPM, will be decreased.

I learned this while connecting DC motors to a joule thief,
and comparing them to an identical motor with straight DC
then realized you can implement the same effect in a stepper motor, or even A/C motors,
tri-phase gets a bit more complicated, but its not impossible.

[Nink]

Wouldn't the downward force of the drone increase drag significantly on the blades with PWM resulting in a significant slow down of the motor.  Maybe if we combined a magnetic pulse motor with PWM the increased efficiency we could offset any degradation in performance but we would also have the increased mass with the magnets, coils  and housing of the pulse motor to contend with.

Maybe all we really need is some helium balloons :-)

[antimony]

Im sorry to pick up on this thread after such a long time,  but i have been kind of busy and have started to pick up on this again,  and i didnt want to annoy anybody by starting a new thread about the same subject. 

I read something today about making these antennas, and how he used them.
I cant link to the diagram, but it had two Litz wire wound chokes, and a step down transformer that stepped down the V from 10kV to 12 or 24V maybe. 

What do you think about it?  He wrote that it was very efficiant and that he got 50W continue