A length of ticker tape is fed into the opening of the timer and the free end attached to the trolley. The ticker timer is powered up and the trolley released down a ramp for example. The timer marks dots along the length of the tape at regular intervals. Examination of the tape afterwards should show dot sequences relating to the movement of the trolley. As the trolley accelerates, the dots should appear further apart. Where dots are equally spaced, the trolley is moving at a constant speed.

Because ticker timers vary greatly from model to model, their frequencies may also vary. Some simply use the A.C output from a labpack to power a motor back and forth to create the dot marks. Others use D.C and an electromagnet arrangement. To work out the speed of a moving trolley by looking at the dot formation, you first need to know how many dots per second your ticker timer creates. Booklets supplied with your ticker timer should mention the frequency at which it operates. If in doubt, ask the supplier of your model.

Speed

If for example your ticker timer frequency is 10Hz (10 dots per second) and the dots are spaced exactly one centimetre apart, you can work out that the trolley was moving at 10cm/s or 10 centimeters per second.

To work out speed, use the formula s=d/t. more notes on this formula and others can be found in our Info Library.

If your ticker timer direct uses A.C from a power pack or low voltage power pack to operate, (see fig 1) the mini motor inside may fail eventually, as may the fuse. New motors can easily be soldered into place following the manufacturer guidelines detailed in the user manual. Fuses are usually stocked by the supplier of the ticker timer, alternatively they can be purchased through electrical retailers.

Ticker timers can also be used to good effect with the airtrack apparatus. Attaching ticker tape to one of the floating trolleys can show how near friction-free the airtrack can be by producing near constant evenly spaced dots.

Ticker tape is available by the roll or pack of rolls from most suppliers. It consists of pressure sensitive paper which ?bruises? when struck much like some till receipts do nowadays. It should be kept in a dry environment away from bright sunlight.