Clutch The KTM 250 EXC-F employs the KTM-developed DDS clutch (damped diaphragm steel) with a wear-free steel basket and extremely heat resistant clutch plates and new, nitrated steel liners. This clever design employs a diaphragm spring instead of the usual coil springs, making for considerably easier clutch action.
The difference between active and passive solar water heating systems is that active systems have circulating pumps and controls, while passive systems do not. Although passive systems are usually not as expensive as active systems and can last longer, they are generally less eficient.
Sometimes these types of heat sinks are referred to as an HSF, which is short for heat sink and fan. Passive heat sinks are 100% reliable, as they have no mechanical components. Passive heat sinks are made of an aluminum-finned radiator that dissipates heat through convection. For passive heat sinks to work to their full capacity, there should be a steady airflow moving across the fins. The above picture is an example of a heat sink that is both active and passive.