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About gmamo

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    RC-Cam Visitor
  • Birthday 11/20/1973

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    Hmmmm....quite a lot of various interests.
  1. By visiting a couple of fora, and viewing videos of helis doing 3D, one can arrive to a conclusion that the new breed of SMM gyros are bloody good... namely the GY-401 and all the above specd gyros. You can see them doing full power climbouts, and tail first backwards maneuvers, and the tail never seems to sway. This is a combination of a powerful Tailrotor, a good gyro and a fast tail servo. Here comes the interesting bit: If I were to have a 3 axis camera mount or gymbal and mount 3 complete tail rotor assemblies( all with a small brushless motor driving the Tailrotor through a belt ( or whatever), with a fast servo and a good gyro matched to the system) in an XYZ fashion, each one controling roll, pan and tilt, you could have the full potential of the current gyro technology. I would for now, remove the effect of downdraught caused by the main rotor of a model helicopter... although I think it is irrelevant considering how 3d helis perfectly control backwards and sideways flight. This arrangement would provide the benefits of having a very strong and very fast lock on a heading ( just like a 3d heli ) with the camera remaining pointed at infinity.... all this if there is no physical restraint from the heli carrier itself...ie.. the gimbals should be totally allowed to pivot freely. Do you like this ??? I think it'll work nicely Now for the next step. IF you, an extrovert PIC expert ;-) , can build a PIC project ... an emulator for a tail rotor system... That is... A tail rotor IMHO is a constant power applied to a propellor with a variable pitch mounted on a tail boom. when the gyro senses even a small movement, you can see that the fast servo moves a large amount at first, the tail rotor pitch increases/decreases, the tail starts moving ( here we have some inertia, when the tail is approaching the new heading the tail servo goes to slightly negative value of the previous amount to stop the tail inertia from moving bringing a sudden dampened stop to the system. It's very hard to explain in words what seems clear in my mind If one can manage to either design a new gyro, to reprogram a gyro pic to tune the PID loop to a camera gimbal, or else insert a PIC to mimic the tail responce, on can place the gyro on the actual axis that is being actuated by the gyro itself for a closed loop performance .... ( just like on a heli, but now without the three tail rotors stickling out I don't know if you have tried to experiment with gyros placed on the actual actuated axis... there is a severe positive oscillation which ruins the stabilization if the gain is turned up so that some stabilization starts to happen. My experiments have only worked to a limited satisfaction, only if the gyro is mounted outside the actuated axis (ie.. mechanically, one step axis up from the actuated axis itself ... if you know what i mean !! ) Any comments about this idea ? Any PIC experts wanna do a Tail dynamics emulator ? George from sunny Malta !!
  2. Here's some links that I remember : 1) http://www.yoredale.uklinux.net/electronic...electronics.htm 2) http://www.uoguelph.ca/~antoon/gadgets/disch.htm ... taken from the site : http://www.uoguelph.ca/~antoon/gadgets/gadgets.htm 3) http://www.geocities.com/SiliconValley/Gar...schematics.html but the link doesn't seem to work anymore Thanks MR. RC_Cam... The best way to drain ( controllably high currents is to use banks of transistors as a constant current load.. or else some Switching Power Mosfets. It is important that we measure a cingle cell capacity in this application. Therefore if we do not want to have a very long process... and to use realistically high currents, we must discharge at 20 Amps for the Sub C Cells That means 1.2V * 20A = 24 Watts of dissipation... Not unbearable George
  3. HI .. Anyone has built a cell matching instrument using PICs ( as not to use many discretes ) ???? There are a couple of schematics on the net, but all use a lot of components, and you'll have to build many copies of these circuits to arrive anywhere with a couple of 10-20 cell packs to be matched. A PIC or a PC can be used to time a discharge to an adjustable cutoff point and give capacity or time taken to discharge. However, it needs to have a high discharge capacity ...5-20 Amps to be realistic. HELP !!!!
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