An electronic audio switch

This article describes an electronic switch that allows presentation of sine wave stimuli without the often undesirable transient thump, thud, or click usually caused by ordinary electromechanical switches.     

A precision electronic timer for the measurement of acoustic signals

An electronic speech timer that uses only relatively inexpensive and readily available electronic components and common circuitry is described. This device rapidly and accurately measures the durational characteristics of speech and the durations of other acoustic signals over extended lengths of time. Its application to the measurement of total speaking time, articulation time, and phonation time are outlined. Accuracy, reliability, and validity are discussed and compared with other, more time-consuming and cumbersome methods of durational measurement.     

Versatile electronic timer for synchronous switching of multiple electrical devices

An electronic timer consisting of CMOS integrated circuits is described that synchronously switches multiple electrical devices on and off on either circadian or noncircadian cycles. Precision is attained to within 1 min when used in the circadian mode or to within 16.7 msec when used at the highest speed (60 Hz). The electronic timer is useful for behavioral studies, control of environmental chambers, and control of general laboratory appliances.     

A versatile electronic switch with memory

This noise-conditioned switch provides a convenient interface between S response switches and logic circuitry and is adaptable to many experimental situations.     

An inexpensive electronic switch with adjustable gain

A simple electronic switch, based on the Motorola MFC 6040 electronic attenuator integrated circuit, is described. The circuit is useful in the slow-speed switching of audio signals where key click and switch bounce cannot be tolerated.     

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.     

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.     

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.     

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).     

An inexpensive digital millisecond timer and event counter

A simple circuit for a digital millisecond timer and event counter is described. The total cost of the unit including all components, a power supply, and an enclosure is less than $30. Daily use in simple reaction time experiments has demonstrated the reliability of the design.