Aloysious A Gruntpuddock
Lego NXT external power supply
I wanted to use more than the 6 batteries the NXT can carry in order to increase the voltage (makes the motors run faster) so I bodged up a connector.
I can now use an 8 AA cell holder to give me 2 extra cells. If they are fully-charged, the voltage will be about 11.2 v instead of about 8.4 as at present. I have used a bridge rectifier to avoid damage caused by wrong connections and this drops it to about 10.5 v. Still right on the upper limit for the NXT so I have made a fake cell with some dowelling and wire to replace one cell and keep the voltage within acceptable limits. Once the voltage drops it can be replaced with a genuine battery.
Being a cheapskate, I used whatever was lying about to make the bits which fit inside the NXT.
Using 7 charged Ni-MH batteries I get 10v at the power pack and 9.3v at the terminals inside the NXT.
If you want to see how it should be done, visit :- www.philohome.com/nxtsupply/nxtsupply.htm
Lego NXT external power supply
I wanted to use more than the 6 batteries the NXT can carry in order to increase the voltage (makes the motors run faster) so I bodged up a connector.
I can now use an 8 AA cell holder to give me 2 extra cells. If they are fully-charged, the voltage will be about 11.2 v instead of about 8.4 as at present. I have used a bridge rectifier to avoid damage caused by wrong connections and this drops it to about 10.5 v. Still right on the upper limit for the NXT so I have made a fake cell with some dowelling and wire to replace one cell and keep the voltage within acceptable limits. Once the voltage drops it can be replaced with a genuine battery.
Being a cheapskate, I used whatever was lying about to make the bits which fit inside the NXT.
Using 7 charged Ni-MH batteries I get 10v at the power pack and 9.3v at the terminals inside the NXT.
If you want to see how it should be done, visit :- www.philohome.com/nxtsupply/nxtsupply.htm