It works like a regular typewriter with all letters, numerals, and punctuation marks as well as shift, space, and return carriage. It’s a better addition to your home office.
Monday, October 13, 2014
Boost up current to 8 Amps from a LM2575
The LM2575 works a regulator only and don’t deliver any current to the load.
If the regulator switches “ON”, you find a voltage at the output of it. This makes T4 switching on also.
The collector of T4 now is nearly GND and also the Gate of FET T3. This FET switches on (it’s a P-FET!)
For T3 you can take everything what’s called Power P-FET with low RDSON, a IRF9540 is a good choice.
The “invention” of this circuit is the Gate turn off of T3.
In ON State, The Gate of T3 has nearly GND potential, D9 conducts and T5 is off.
If now the Regulator switch it’s output OFF, then the Base of T4 is pulled low by R12 and no currents flow through T4.
Also the cathode of D9 is connected to Vcc via R13. The stored energy in the Gate capacity of T3 lets now pull T5′s emiter lower then the base. Whats happens if the Base of a NPN transistor has higher voltage than the emiter? It conducts ! Now, T3′s gate is directly connected to the source via T5 and the gate capacity can be discharged very fast.
Sunday, September 7, 2014
USB Keyboard Made from Old Typewriter
It works like a regular typewriter with all letters, numerals, and punctuation marks as well as shift, space, and return carriage. It’s a better addition to your home office.
Thursday, September 4, 2014
Low voltage audio amplifier circuit from 0 9 volts
Here i share power amplifier based on IC TDA7236 . This amplifier require minimum voltage 0,9 volt and maximum voltage is 1, 6 volt , its very low voltage amplifier. You can use this amplifier everywhere just with one battery 1,5 volt. Power output 16 mW with 32 ohms impedance. see circut below :
