Abstract: A golf putting training device that indicates the proper aim point on sloped putting surfaces such as golf course greens and compensates for the slope of the various putting surfaces. The device comprises a platform supporting one or more spirit levels. The device can be elevated upon the putting green surface to permit a golf ball to roll underneath the device when the ball is putted towards the indicated aim point; or not elevated when aim points are referenced to the golf cup or hole.

Abstract: A circuit for controlling one or more light emitting diodes is disclosed. The circuit is designed to supply current to the diodes from an input voltage source in response to a control signal. The circuit provides a predetermined level of current to the diodes which is substantially independent of the magnitude of the input voltage. The circuit also includes a switching function which operates to switch off the diode current when the control signal exceeds a first level of control voltage. When the control signal is reduced below a second level of control voltage, the diode current is switched to the predetermined level of current.