September 2007 Issue

A summary of this month's contents.

Pocket T.E.N.S. Unit

Transcutaneous Electrical Nerve Stimulation (TENS) is a technique for reducing the sensation of pain, by applying electrical signals to the affected area.


Our latest TENS model is battery powered and uses an oscillator design to generate TENS signals adjustable for voltage level, pulse rate and pulse width. Intermittent or continuous control. Output adjustable from 12V to 80V, 4.6Hz to 410 Hz, pulse width 70 to 320µs.

To be used with a 9V battery only. Must not be powered by a mains adaptor.




A T.E.N.S. unit must NOT be used in any of the following circumstances:

  • Where the cause of pain has not been diagnosed by a qualified health care practitioner
  • By any person with a heart pacemaker
  • By any person with a serious/unstable heart condition
  • By any person with epilepsy
  • When electrodes are placed across the chest/ heart, e.g. both arms simultaneously
  • When electrodes are placed on the neck in the region of the carotid arteries
  • Where any area of skin is inflamed or infected
  • When Pregnant
  • If an allergic reaction develops to adhesive tape or electrodes
  • Around the head.



This multipurpose timer is much more flexible than previous designs. It can be programmed for a single time period from one second to just under 100 minutes, or a sequence of two such (independently programmed) time periods, or up to 99 cycles of one or two time periods. Easy to program. LCD display. Twin changeover relay outputs. PIC 16F84A-based.


USB Breakout Box

A very simple method of measuring to ensure your peripherals are not overloading your USB ports.


Also in this issue:

V2 PC Scope - Part 2 - rounding off our PIC and PC controlled hobby oscilloscope. Techno Talk - the pitfalls of eco-friendly lighting. PIC n MIX - single wire communication protocol interface for PICs. Using MPLAB Part 4. The Power of Mechatronics (Part 4): adding speech to your application. Practically Speaking - using diodes successfully. Net Work - the Internet column describes how to download our free source codes. Circuit Surgery - Linear Voltage Regulators and Capacitors (Part 2).


Source codes

PCB artwork


PCB artwork


As from July 2013 issue PCB artwork is available free to subscribers only.


Non-subscribers may purchase artwork files for a nominal sum. Please contact our Orders Dept for information or to place an order.


EPE Printed Circuit Boards


We can supply ready-made printed circuit boards (8-digit order codes) to the original design specification via mail order or from our Online Shop.

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