Abstract: A planar transformer having windings on a printed circuit board coupled by a high frequency ferrite core driven by a high frequency operational amplifier based relaxation oscillator controlling a switch for pulsing a primary winding of the transformer at a set frequency. The secondary of the transformer powers a lamp circuit which is isolated from the electrical supply, and a test input is connected in a logic OR arrangement with the electrical supply.

Abstract: A golf practice device in the form of an attachment to a golf club shaft. The attachment has preferably two weighted elements that are coupled together in such a manner that the spacing of the elements may be adjusted as desired, depending on the thickness of the shaft to which the device is to be attached. Thus, the device may be positioned at virtually any location or a tapered golf club shaft and also on golf club shafts of varying thicknesses. Once the desired spacing is selected, a frictional engagement device is used to secure the weighted elements at the desired spacing. The golf practice device is formed to be aerodynamically efficient, and preferably has substantially a smooth, rounded exterior surface. The locking device accordingly is formed such that it does not interfere with the aerodynamic efficiency of the device.