Chip on Board Kits
Southern China is now the major centre for making chip-on-board (COB) electronics. And DIY Electronics is the only supplier that we know of that is supplying these items to the public in general & the hobbyist in particular. We have put together a range of these items. If you are interested to buy these or similar items in bulk then please email us with your requirements.
COB means that the very small die form of the IC is bonded directly onto a PCB and the copper tracks come out from it. A blob of black epoxy covers & protects it. The benefit is a saving in space. We are buying these COB's on larger than usual PCB 16mm x 29mm, so that the student can solder the external components to it with a minimum amount of difficulty. They were reviewed in Electronics Australia, April, 1995, p72.
SG1 through 14 are COB Kits which give a sound of some sort. Kits 52M & 37M flash 5 LED's in various patterns. An 'M' suffix denotes that the Kit comes with a mother-board to support the COB PCB and components. You can view a scan of the motherboards below.
SG1M - Three Train Sounds Whistle-blowing, chugging, level crossing bell and clackety clack of train crossing bridge. Just 4 switches and 4 components to add. COB PCB: 16mm x 29mm. Mother board supplied to fit COB PCB & components into.
SG2M - Cellular Phone Sounds
Imitates real phone tones, engaged and ringing sounds, two door chimes. COB PCB: 16mm x 29mm. Mother board supplied to fit COB PCB & components into.
SG3M - 16 Door Chimes
Sixteen door chime tunes. Tunes cycle through the sixteen tunes with each keypress. LED fluctuates according to the sound level. Designed for high quality melody products. Supplied with motherboard.
SG4M - 3 Sirens & Machine Gun The classic noises little children love! Three sirens- ambulance, police and fire engines-plus a machine gun. All with 2 flashing LEDs. COB PCB 16mm x 29mm with motherboard.
SG5 - Ding/Dong Door Chime The classic door chime ding dong. Adjust the component values in the two RC networks to get exactly the tones you want. 3V low stand-by current. COB PCB 16mm x 29mm
SG6 - Melody IC Melody IC in TO-92 package. Just connect 3V and speaker. Tune repeats continuously while power is connected. Total of 128 notes. Cmos LSI. For Alice tune.
SG7 - Complete Card Melody Unit- "Love Story" Melody IC COB, battery and piezo all ready to play. As found in Christmas cards and books which play when you open the page. Self-adhesive backing. Tune repeats continuously while power is connected. Total of 128 notes. Cmos LSI. Two supplied per kit.
SG10M - 4 Animal Sounds. Same mother board and COB as SG1M. Only the sounds are different.Hen, cat, cow and dog sounds. Just 4 switches and 4 components to add. Ideal for schools. Supplied with motherboard.
Scan of Motherboard
SG10M Documentation in pdf format
G11 - Siren Sound Generator 18mm x 15mm COB contains a standard siren driver as found in piezo horns and toys. Drive circuit will tolerate a wide range of components values. 2V to 5V operation
SG12 - Gun & Bomb Sounds Similar to SG1 2 10 but with gun & bomb sounds inside. COB PCB: 16mm x 29mm.
SG13 - Complete Card Melody Unit- "Happy Birthday" Melody IC COB, battery and piezo all ready to play. As found in Christmas cards and books which play when you open the page. Self-adhesive backing. Tune repeats continuously while power is connected. Total of 128 notes. Cmos LSI. Two supplied per kit. Same as SG7
SG14 - Complete Card Melody Unit- "Three Christmas Carols" Same as SG7 & SG13 but three Christmas Carols play
K52M - Five Ultra Bright LED Flasher
Five Ultra Bright LED's flashing in random or in sequence. Uses a COB (Chip-on-board) PCB measuring 3cm x 1.5 cm. The flashing frequency is set by a single external resistor between 300K and 1M ohm. A pad connected high determines the random or sequential flash pattern. A second pad connected low determines whether the flashing is continuous or set by a toggle switch.
Excellent project for schools since the project is very safe - uses 2 x 1.5V batteries, can be easily put together within 30 minutes, teaches the latest electronic technology as found in games and toys and give an strong visual result when it is finished. Comes with a motherboard to aid attaching the components to the COB PCB
Five Ultra Bright LED's flash in seven patterns. The modes can be cycled through using an on-board SPDT switch. When the desired flashing pattern is found just leave the switch there and the pattern will remain flashing as long as power goes to the board & the switch remains set. COB PCB measuring 3cm x 1.5 cm. October 2000. Now with trimpot to vary flash rate.