An inexpensive 28-V timer circuit using solid state and relay devices

An easily constructed 28-V dc timer circuit is described. The circuit is as precise, reliable, and versatile as some commercially available units, but is much less expensive to construct.     

Microreaction timer

A small unprepared simple reaction time (RT) system is described in which the visual stimuli are presented at quasi-random intervals of 3–13 sec. The device is battery-portable for administration in the field and for immediate presentation of mean RT and standard deviation after the test. These data plus all individual RTs are stored in digital memory for printout or further analysis in the laboratory. Up to 24 10-min tests may be accumulated in memory.     

A variable-interval timer

A variable-interval timer with an audible tone output was designed to pace participants in human-factors studies. The timer can be operated in a continuous (recycling) mode or in a time-out (“beat-the-clock”) mode. In the continuous mode, the audible tone is emitted at the end of the preset interval and a new timing cycle is begun. In the time-out mode, the research participant must depress a switch both to avoid the tone and to begin a new cycle. The time interval can be digitally programmed for intervals from 1 sec to 2 h and 45 min. The operation of the timer is described, and construction details are provided.     

Timing without a timer.

Inferred-process theories propose various internal timing mechanisms to provide discriminative stimuli for temporal control of behavior. Biobehaviorally informed computer simulations indicate that timing may emerge from the action of reinforcement on neural circuits without the need to postulate timers of any sort.     

Miniature reaction timer with memory

A pocket-portable instrument is described for the self administration, in the field, of simple reaction time trials with variable warning foreperiod. The device will store 100 reaction times in milliseconds for later readout in the laboratory, in addition to displaying them to the S at the time of the trial.     

Transistorized timer for sensory-behavioral research

A timer circuit is presented that can produce pulse durations ranging from 1 to 20,000 msec. The timer has high reliability, is inexpensive, and simple to construct.     

A token-actuated timer for line-voltage devices

A token-actuated timer that detects the insertion of a flat washer (“token”) is described. The unit provides a timed line-voltage output and counts the number of times the line-voltage device has been operated. Using behavioral token economies, this device has been used to control the television watching of children by monitoring television watching time, and by controlling the amount of time the television is on.     

Apparatus noiseless electronic switch and timer

In psychoacoustic testing and experimentation the avoidance of extraneous stimuli is most important, but the elimination of such cues is often difficult. A circuit is described which enables sound stimuli to be switched on and off in a manner which produces no unwanted transient signals. The circuit may be adapted to function as a noiseless changeover switch.     

An accurate repeat cycle timer.

This timer was designed to provide a compact and quiet unit to control the presentation of visual stimuli by means of a slide projector, but it is not limited to this use. It is a solid state device, ready for use as soon as switched on, and is made largely from commercial logic units. The output is in the form of contact closures: the ON relay and the OFF relay give short pulse closures at the beginning of their respective cycles. With circuit values as shown in Fig. 1, times, from 0.5 to 10 sec in increments of 0.5 sec with an accuracy of ±1%, are selected by separate switches on the ON and the OFF cycles. Single interval solid state timers have been described by Saslow and Markowitz (1964) and by Tapp and Clark (1964).     

Using a token-actuated timer to reduce television viewing

A child watching an excessive amount of T.V. was provided a behavioral program featuring a token-actuated timer. Earned tokens were used to activate the T.V. for thirty-minute periods. The token-exchange system effectively reduced T.V. viewing and the reductions were maintained at two follow-up points. The principal contribution of the study is the development and evaluation of an electronically controlled device that was used to check the accuracy of parent-reported data.