Matt circuit

This automatic NiCd charger for 9V NiCd batteries is using 555 timer properties and is very easy to build. Why is an automatic 9 volts NiCd battery charger? Because you can leave the battery for charging as much as you like: it will be always completely charged and ready for use when is needed. It wont be overcharged and it will not discharge.  9V Automatic Battery NiCd Charger Circuit Diagram : With the values presented in the circuit diagram, the battery charger NiCd circuit is suitable for 6V and 9V batteries. 9 volt types with 6 and 7 cells are charging with 20mA; P1 must be adjusted so that the NiCd charger disconnects after 14 hours. Window inferior level is set at 1V below this value with P2. 5V battery type with 4 or 5 cells are charged at 55mA. Again, with P1 adjust the NiCd charger circuit so it disconnects after 14 hours. Window inferior level must be set at 0.8V below this value.

How to build a simple and low cost 1.5v to 9v DC Converter Circuit. This inverter circuit will convert 1.5v to 9v to take the place of those expensive 9v batteries.The input voltage for this inverter can be from 1.5 volts , up to 4.5 volts . 1.5v to 9v DC Converter Circuit Diagram: When no current is being drawn from the output the current is less than 10mA. This inverter circuit is very simple requiring few components , but it can be used only for projects that require low current . The L1 coil must have 60 turns on a 10 mm ferrite slug 15 mm long , using a 0.25 mm diameter enameled wire .