Capacitance
Meter - our discrete logic design allows any capacitor type and value
to be measured on an LED display. Measures from a few picofarads to 10,000µF
and is accurate across the whole range.
In the December
2001 issue (P.882) we published the following correction. Page 764, Fig.
6 as shown, the interconnecting top-side "ground plane" pads/
holes (top left and right) on the main printed circuit board do not align
with the underside foil pattern (Fig. 7), and you will need to correct
Fig. 6 ground plane foil pattern if you intend making your own double-sided
pcbs. The boards sold through the EPE Online Shop and PCB Service are
correct. Also note that capacitor C12 in Fig. 4 (page 763) should be corrected
across the pads just below and to the left of IC3 pin 16 and not
as shown.
Pitch Switch
- a novel sound-operated switch with precise frequency response. Highly
selective design for precision control and response to specific frequencies,
such as those generated by a specific "Penny Whistle".
In December
2001 issue (P.882) we said that as supplies of the 4063 quad comparator
have dried up, a suitable alternative might be the 7485 though this has
not been tried or tested.
"Lights
Needed" Alarm - ensure your car can be seen when driving in poor
lighting conditions - our reminder unit warns you to "light up"!
Integral piezo sounder.
Teach-In 2002 - Making Sense of the Real World. Our new 10-part series commences this month, dealing with environmental monitoring and a variety of sensors, showing how they work and how to use them. We examine temperature in Part One, also offering practical "Labs" which you can build for yourself.
Teach-In
2002 Power Supply - useful for the practical "Labs" that
accompany our educational series Teach-In 2002, this unit offers ±12V
and +5V at 600mA total. Offers a suitable low voltage supply to run the
Labs from the mains.
In December
2001 issue (P.882) we pointed out that the heatsink mounting arrangement
as illustrated, was incorrect. The plastic insulating bush should be inserted
from the top, down through the tab, in order that the mounting screw is
completely insulated from the chassis. The correct version was published
in Circuit Surgery Dec. 01.
FREE 16 Page Supplement PIC Toolkit TK3 for Windows - full operating details of our exciting new Windows-based free software for programming PIC microcontrollers. Also in this issue, Ingenuity Unlimited (readers' own circuit ideas), New Technology Update describes fuel cells and biological switches. Net Work — The Internet Page — helps you take control of your Email using POP3 clients.Circuit Surgery - how to wire transistors in parallel.