| Absolute-value circuit delivers high bandwidth: 05/15/03 EDN Design Ideas (added 1/05) Most absolute-value circuits have limited bandwidth and high component count,
and they require several matched resistors. The circuit in Figure 1 uses three fewer components than most absolute-value circuits require, and
only two of the resistors must have 1% tolerance to obtain 1% accuracy. This circuit's output voltage is an accurate representation of the
absolute value of the input signal,...... |
| Absolute-value comparator touts accuracy, size: 03/07/02 EDN Design Ideas (added 1/05) A typical window comparator uses two comparators and a single op amp to
determine whether a voltage is inside or outside a boundary region. Figure 1 shows a typical implementation. IC1 is an inverting op amp with a
gain of –1. VREF and –VREF create the window limits. When VIN becomes more positive than VREF, the output of IC2A goes low. ...
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| Design low-duty-cycle timer circuits:
08/22/02 EDN Design Ideas (added 1/05) Designing astable circuits using the industry-standard 555 timer is a straightforward process
when duty cycles are 50% or greater. However, you must overcome the many pitfalls of low-duty-cycle circuits to arrive at a desired result.
Using only ideal components eases the design, but the components themselves are hard to obtain.... |
| Electronic fuse emulates fast or slow blow fuses: 11/09/00 EDN-Design Ideas / (Electronic circuit added 7/03) The electronic-fuse circuit in Figure 1 combines the properties
of a current transducer and a solid-state relay to disconnect low power at preset levels. Using this circuit lets you avoid the bother of
stocking and replacing fusible links. The circu... |
| Expanded-scale indicator revisited:
08/08/02 EDN Design Ideas (added 1/05) The visualization aid that a previous Design Idea describes allows only the expansion of the
upper end of the scale (Reference 1). But what can you do if, according to your project requirements, you need to expand the middle region of
the scale? Figure 1a illustrates the challenge. A voltmeter comprises a 100-µA dc meter and a series resistor.... |
| Missing codes tester checks 16 bit ADC in 7 sec: 06/10/99 EDN-Design Ideas / (Electronic circuit added 7/03) As the resolution of ADCs increases from 12 to 16 bits and
higher, the difficulty in testing the"no- missing-codes"specification grows proportionately. To fully guarantee no missing codes for a 16-bit
ADC requires testing all 2 16-1 possible output... |
| Two buttons provide safe start:
07/06/00 EDN-Design Ideas / (Electronic circuit added 7/03) The circuit in Figure 1 provides a safety interlock that checks the actuation of
two pushbuttons before enabling a relay. When you push both buttons, the circuit actuates the relay. At that point, you can release one of the
switches without the relay'... |
