-40%
3.3V Cmos Logic Probe Dual Input 3-5V Operation With Pulse LEDs and Pulse Audio
$ 27.98
- Description
- Size Guide
Description
Two independent circuits for use with 3-5V Cmos logic. Circuit A is the probe along with an external input, circuit B is only an external input.A has Hi, Lo, and rising edge LEDs
B has Hi, Lo, and falling edge LEDs
Both have a switchable beeper that follows the edge LED
Both edge detectors are available as open drains externally
Edge detection is a .4s pulse applied to the LED, beeper, and external fet
Power is taken from the logic circuit being observed
External connections are via a DB9 male connector. The included 12" DB9 female cable is terminated in .025" square female connectors that mate with standard .025" pins. I include 4 Tektronics grabbers that fit on the .025" females
Measures 3.8" x 1.7" x 1" with a 1.6" probe
If you're inclined to modify stuff, the probe is all through hole construction, ICs are socketed, and you get a schematic.
I use zeners to provide some overvoltage protection. When the supply voltage exceeds 8.5V the overvoltage LED comes on as a warning.
Inputs are biased to the midpoint of the supply voltage via 1M resistors, so probing hi Z circuits can affect those circuits.
Minimum pulse detection is about 15 us, if you need fast this isn't for you.
Rather large for a probe, but it's not uncomfortable to hold, and you can use the external connections and lay it down to look and listen.