36V direct current from the battery is reduced via this converter to 12V DC to drive loads such as lights, horn, to operate radio etc.. The transducer has for 36V and 12V a common ground and is strong enough (20A) to operate a radio, amplifiers, etc. At the transducer still a free link for +12 V. to which a 12V plug socket or a radio can be attached. One measures the voltage (0V) likewise at the central ground under the seat. On the circuit board are two LED. The LED at the edge lights up if the converter overheats (over 75C), the output is then switched off. The second LED signals that supply voltage (battery voltage) has fallen below 22Volt.
Note: green cables in a City-el are +12V
Ground, link of further earth cables on the left side.
Example of a 12 V plug socket