Hello all, I installed a Sabertooth 2x25 a few weeks ago. The unit appears to do fine other than a few jerks from the motors on occasion, I believe it may be radio interference. I'm using a FM ground Freq radio purchased just for this unit. I still need to tie in some caps to the motors and make sure the radio antenna is installed correctly so at this point I'm not really concerned about it.
But and a very big but here, I ran into something the other day that gave me pause. Although the Sabertooth has a BEC, I have been using the battery pack that came along with the radio to power the receiver. This setup is fine and I've experienced no issues other than mentioned above. The next step was to install my sound unit (a home brewed unit using a few PICAXE chips and 2 Vmusic sound modules) into the tank, again using the battery supplied for the receiver. The unit has a 12 volt regulated power supply included and uses a simple Y connector for the radio signal. I've used this unit with success in my past setup using Joe Sommers ESC. I tested the unit without applying power to the ESC. The unit worked fine! But then I decided to apply power to the Sabertooth and run the tank. It took about 3 seconds before the negative wire leading to the sound unit began smoking. Lucky for me no damage occurred to the receiver or ESC. I figured I wired something wrong, but upon inspection decided every thing was as I have had before in a past setup. I then removed the sound unit from the system and decided to install my home brewed BEC circuit (A simple 12 volt regulator circuit supplying 4.5 volts) into the receiver. Once again I tied the power supply to one battery for a 12 volt source. Power up the ESC and watched smoke as the NEG wire to started to sizzle. Again no damage to the either receiver or ESC. I tested both units wired as before with the original receiver battery and then with the on board BEC and the ESC and REC seem to operate thankfully. I use two 12 volt batteries for a 24 volt system. I'm about 95% sure that in the past I simply tied the power supply (12 volt input) for the sound unit to one battery. Not sure why I didn't just power the sound control unit with 24 volts as the 12 volt regulator will accept up to 35 volts. Be that as it may, I'm still pretty sure it was only supplied 12 volts. Now I know from building the sound control and even a smoke control unit that the entire circuit has to share a common ground or else the PICAXE chip will not work correctly with the radio signal. But this has burning up of the negative wire has me spooked. And yes before I go any further I plan on installing a control fuse in the negative side to help prevent any further damage. So I guess one of my biggest questions is could the circuit being fried is due my hooking up only side of the battery set to the sound unit? Could the ESC cause this short of shorting? Any help, thoughts would be greatly welcome! Rusty -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat
