Telephone Kits

K33 - Tape Recorder Switch for Telephone Price Photo Docs
This kit uses a FET to switch on a tape recorder when the phone is picked up. It will work with low voltage tape recorders as low as 1.5V. It requires the REMOTE & MIC jacks of the tape recorder to be available. Plugs are provided.

K55 - Suction Cup Telephone Pickup Price Photo Docs
Uses a suction cup to attach to your telephone handset. Picks up the magnetic field produced in the earpiece by both sides of a telephone conversation. Feeds into an 8 ohm speaker after amplification. Volume control trimpot built in.

K140 - Telephone Switcher Mk 2 Price Photo Photo Docs
This kit connects to the telephone line and can be used to control up to four (4) relays using a tone dialling (DTMF) telephone.
Dial up your phone from anywhere in the world, enter your password then turn on or off any of the relays to control devices in your house or office.

A number of user settings are available to improve the useability and security of the device:
- Password protection (up to 8 characters)
- Tamper setting
- Rings to answer
- Auto hangup time on idle
- Timed lockout if tamper setting tripped

Comes complete with a small plastic case (13x10x3cm) with silk-screened front and rear panels. Connection to the relay contacts is via pluggable 3-way screw terminals. Operates on 12VDC (12V/300mA plug pack will be fine).

K153 - DTMF Tone Grabber MK2 Price K164 Back View K164 Inside View
Detect DTMF tones direct from a telephone line or via the onboard microphone. Connection to the phone line is via a 600:600 ohm line isolation transformer (Photo Docs). Last 32 digits detected are stored and displayed on a 16x1 LCD. Display can be scrolled left and right. Each digit is also output as ASCII data via a RS232 serial port at 9600 baud. Here is a ".wav" file you can use to test the microphone input. Unzip it and play it back using a media player such as Windows Sound Recorder.

K164 - Telephone Call Logger PriceK164 Front View K164 Back View K164 Inside View
Records the start and stop time of ALL outgoing calls along with the number dialled (plus any other digits pressed during the call). It operates "stand alone" - no need for any connection to a PC. Featured in December 2001 issue of Silicon Chip - click here Docs for article.

Data is stored in non-volatile EEprom memory (24C128) so there is no loss of data during power failures. The kit is supplied with 16K of memory and is expandable in 16K blocks up to 64K total. The logger "auto detects" the amount of available memory - just plug it in and go.

With 64K of memory installed, the logger can record over 2800 10-digit telephone numbers ( that's 28,000+ digits ). With the standard 16K of memory, the logger will record about 2 months worth of calls for the average household.

Logged data can be downloaded via a serial port and saved to disk.
Use any terminal emulation software on any computer eg. Hyperterminal supplied with W95/98/2000/XP (click here for setup information). The data is formatted so that it can be easily imported into Microsoft Excel ©. As a bonus, call data is also output in "real time" to the serial port as well as being recorder in memory. This is useful when immediate call analysis and/or external data logging is required.

Here is a sample printout of the logged call data, showing the START and STOP date/time, followed by the number dialled.

27-Aug-01 15:14:08,27-Aug-01 15:40:07,86254690
27-Aug-01 20:39:34,27-Aug-01 21:04:27,96830890
27-Aug-01 21:16:43,27-Aug-01 21:19:52,
28-Aug-01 08:46:36,28-Aug-01 09:04:28,96830890
28-Aug-01 10:43:40,28-Aug-01 10:59:21,96830890

The third line appears to have missed the number dialled. In fact this was an INCOMING call. The logger does not have "caller ID" circuitry and is unable to record the phone number of incoming calls.

Access to the data logger's internal functions, including data downloading, is PASSWORD protected.

The kit is supplied in a plastic case measuring 130(W) x 100(D) x 30(H)mm with silk-screened front and rear panels. The kit is powered by a 9-to-12V DC power supply. A 12VDC wall adaptor rated at 300mA is suitable.

Two RJ12 (USA type) are provided on the rear panel, marked "LINE" and "PHONE". This allows a telephone to be connected and used even when the logger is put in its place.

Note: Telephone line cords and power supply are NOT supplied with the kit.