Very simple 555 based doorbell kit

The design of this circuit is quite clever. It's very reminiscent of the type of projects often found in electronic magazines of the 80's and 90's. It uses the venerable NE555 chip to produce a two tone chime effect when a button is pressed. The way it gives two different tones is quite clever. Note that the standby current is a couple of milliamps, so this module is not suited to continuous battery operation. The 555 chip contains a group of features inside that can be configured and used in many different ways. Although it is often used as a timer, it also has the ability to work as a threshold detector. It can sink and source enough current from its output to drive significant loads of around 100mA. Although invented in 1971 the chip is still widely used over 55 years later. It's so common that it can be bought in bulk at low cost. If you want to try one of these kits then here's a link to the item on AliExpress (not a sponsor). This is an affiliate link, but that will not affect the price you pay. https://s.click.aliexpress.com/e/_c3O... These kits usually cost around £1 and can often appear as bundle deal items. If you enjoy my videos, supporting the channel on Patreon helps keep it independent of YouTube's quirks, avoids intrusive mid-video adverts, gives early access, bonus footage and regular quiet Patreon live streams.   / bigclive   Alternatively, for a single coffee contribution you can use PayPal:- https://www.paypal.com/paypalme/bigclive #ElectronicsCreators