After checking out a few beautiful business cards while working at his engineering co-op, [Cody] realized he would soon need his own. Instead of a card with subtle off-white coloring, a tasteful thickness to it, and even a watermark, [Cody] decided to make a 555 timer business card.
[Cody] started his business card project by going through a few design iterations while figuring out what he wanted his business card to do. There were a few designs not chosen – one with a microcontroller, a few with just LEDs, and some with no circuitry at all. After checking out a few project from the EEV blog 555 contest, [Cody] decided to go with a simple 555 timer circuit.
Being a business card, [Cody] kept the circuit very simple; it’s just a 555, phototransistor, and a few SMD LEDs. When a 9 Volt battery is placed on the contact points of the card, the 555 lights up the LEDs. When a laser is shone on the phototransistor, the LEDs start blinking. A very neat and sufficiently interactive circuit that is perfect for keeping component costs down.
After the break you can check out [Cody]‘s business card in action.