All posts on April, 2008
John Bokma writes:Some time after reading “A Powerful New Light Source for Ultraviolet Detection of Scorpions in the Field” I decided to build my own scorpion detection device using a bunch of UV LEDs instead of buying an UV flashlight. I ordered fifty 5mm UV LEDs (light emitting diodes) at the website of LSDiodes.[more]
The following application note demonstrates various ways to use the MAX6369โMAX6374 series of pin selectable watchdog timers for general purpose, low power, timing functions.The MAX6369-74 series of pin-selectable watchdog timers are designed to supervise microprocessor activity and indicate when the system is not working properly. During normal operation, the microprocessor should repeatedly toggle the watchdog input (WDI) before the selected watchdog timeout period elapses to indicate that the system is executing code properly. [more]
A stretchable electronic circuit is considered as a number of rigid or flexible component islands which are connected by elastic interconnections. Stretchable interconnections are achieved by embedding meander shaped metal wires in an elastic base material. Stretchabilities of 50% and more using our technologies have been obtained and also the possibility to embed components has been demonstrated.[more]
This basically the frequency meter section of the frequency meter/pulse generator based on the AT90S2313 described elsewhere on this site, combined with the 100 MHz RF interface described in the page about the RS-232 to 100 MHz RF desktop channel adapter. Built and align this is the same manner as the 100 MHz RF desktop channel adapter. The frequency meter has a maximum input frequency of 4 Mhz and counts up to 65535. Time bases of 10 ms, 100 ms, 1 second, 10 seconds, and 100 seconds are selectable from the keyboard via the RF link.[more]
Three inductor-free circuits that allow a white LED or UV LED to be driven from one (1.5 volt) or two flashlight cells (3 volts total) are described on this website. The two cell (3 volt) circuit four transistors.The simple single cell (1.5 volt) circuit requires six transistors, but it isn’t as bright as the two cell circuit. The higher output single cell (1.5 volt) circuit requires 13 transistors, but it is as bright as the two cell circuit.[more]
