Henry Santana is a senior engineer with Kavlico Corp., Moorpark, Calif., and a registered professional engineer in Colorado. He received a BSEE from Colorado State University, Fort Collins. Email address: hsantana@kavlico.com Web site: http://www.kavlico.com/
3 results found for Henry Santana, displaying items 1 - 3
September 15, 2005[Ideas For Design] Wide-Range Pulse-Width Modulator Uses 555 Timer
Simply adding a diode and potentiometer to a 555 timer operating in the asynchronous mode yields a pulsewidth modulator (PWM) with a duty factor adjustable from 1% to 99% (Fig. 1). Applications would include speed control of electric motors where the switching drive can be power efficient. The output of this circuit could drive a MOSFET to control the current through the motor, resulting in smooth control of the motor speed at...
April 28, 2005[Ideas For Design] Op Amp And Two JFETs Form A Voltage-Controlled Amplifier
A simple linear voltage-controlled amplifier can be constructed with one op amp and two JFETs (see the figure). The amplifier can achieve an 80-dB dynamic control range with less than ±0.2% linearity error for 0 V ¾ VC ¾ 0.8 × VP. JFETs act as linear resistors over a very small range of drain-to-source voltages (the ohmic region). In this circuit, an op amp constrains the...
July 19, 2004[Ideas For Design] MOSFET Circuit Forms Reliable Switch Debouncer
Mechanical switches can be noisy, generating multiple transient pulses that may cause faulty operation of fast digital circuits. In this design, a pair of MOSFETs are used in a monostable mode to quench the switch-bounce pulses. The switch...
Henry Santana is a senior engineer with Kavlico Corp., Moorpark, Calif., and a registered professional engineer in Colorado. He received a BSEE from Colorado State University, Fort Collins.
