Hello,
My son has a hot wheels sky crash set and it uses 4xD size batteries. It works well for 10 minutes, then the batteries are drained. You can let it rest for a while, but the play time after that is terrible and not reliable.
The cost of D size batteries is outrageous. Especially if you have to replace them often.
I thought to myself I'll put that grade 12 physics to use and come up with something better.
My goal is to get my 18v 5 amp hour (20V fully charged) drill battery to power the toy. You can drill all the palings of a 20m fence on one charge and have the luxury to recharge it.
I knew straight away that the battery would burn out the toy and that I needed to come up with a solution.
I am new to actually making a circuit, rather than just using ohm's law in theory. I can take a burn to, so please be as honest as you need to be.
I used a multimeter to test the total resistance of the toy circuit. My result was 3.4 ohms. The toy ran on 6 volts, so I calculated the current the toy would pull as 1.765 amps.
I reversed the calculation using 18 volts. To keep the current the same, the total resistance would need to become 10.2 ohms. So somewhere before the actual toy, I need to make a resistance of 6.8 ohm to soak up 12 volts before it hits the toy.
I brought a bag of random resistors and they are all rated to .25W. But when I started some more math I hit a problem.
The total power with the 18v battey is 31.77W. The 12V section needs to soak up 21.18W while the 6V section uses 10.59W. That's alot of resistors.
I have smashed google for a solution but I'm not getting anywhere.
I just don't know if I'm doing this the right way. 10.59W for a toy seems alot. Any thoughts of a potential solution to this will be very much appreciated.
Cheers.
My son has a hot wheels sky crash set and it uses 4xD size batteries. It works well for 10 minutes, then the batteries are drained. You can let it rest for a while, but the play time after that is terrible and not reliable.
The cost of D size batteries is outrageous. Especially if you have to replace them often.
I thought to myself I'll put that grade 12 physics to use and come up with something better.
My goal is to get my 18v 5 amp hour (20V fully charged) drill battery to power the toy. You can drill all the palings of a 20m fence on one charge and have the luxury to recharge it.
I knew straight away that the battery would burn out the toy and that I needed to come up with a solution.
I am new to actually making a circuit, rather than just using ohm's law in theory. I can take a burn to, so please be as honest as you need to be.
I used a multimeter to test the total resistance of the toy circuit. My result was 3.4 ohms. The toy ran on 6 volts, so I calculated the current the toy would pull as 1.765 amps.
I reversed the calculation using 18 volts. To keep the current the same, the total resistance would need to become 10.2 ohms. So somewhere before the actual toy, I need to make a resistance of 6.8 ohm to soak up 12 volts before it hits the toy.
I brought a bag of random resistors and they are all rated to .25W. But when I started some more math I hit a problem.
The total power with the 18v battey is 31.77W. The 12V section needs to soak up 21.18W while the 6V section uses 10.59W. That's alot of resistors.
I have smashed google for a solution but I'm not getting anywhere.
I just don't know if I'm doing this the right way. 10.59W for a toy seems alot. Any thoughts of a potential solution to this will be very much appreciated.
Cheers.