Reg Office: Pointer Farm, Great North Road, South Milford, LEEDS LS25 5LH United Kingdom
Reg Number: 4222329 Tel 01977 683665 Fax 01977 681465 www.milinst.com
MILFORD INSTRUMENTS Ltd
Rev1.6 05/03/2008
SOUND CARD, Part Number 1-480
The Sound Card allows the recording and play-back of up to 8 passages of text or music by means
of up to 8 push-buttons. The Sound card is intended for use in displays, exhibitions and
incorporation into projects that would benefit from aural instructions.
The board may also be configured for either sequential or random message playing.
The Sound card incorporates an electret microphone for recording speech, a 250mW audio
amplifier and a 1V p-p line output for play-back.
Connections
Connect a speaker between the speaker terminals; minimum impedance 4 ohms. Maximum audio
power is approximately 250mWatts into a 4ohm speaker.
The 8 pairs of message button pins may be connected to a number of remote switches. The
switches should "make" when pressed. The pin towards the edge of the board is connected to
electrical ground.
The Sound card requires a 6-12V DC supply to work satisfactorily. When in standby mode (ie not
recording or replaying a message) current consumption of the sound card is approximately 5mA.
Recording
To record using the on-board microphone ensure the Input jumper is set to the MIC position.
If recording normal speech, it should be possible to obtain a good recording by speaking at a
normal volume level about 30-50cm from the microphone. Take care to avoid mechanical switch
noise- this will be recorded and played back as a loud click!
The volume control is not used during recording.
