Modern SIM cards allow applications to be loaded when the SIM is in use by the subscriber. These applications communicate with the handset or a server using SIM application toolkit, which was initially specified by 3GPP in TS 11.14 (there is an identical ETSI specification with different numbering).
(Redirected from Voltage follower) A buffer amplifier (sometimes simply called a buffer) is one that provides electrical impedance transformation from one circuit to another. Two main types of buffer exist: the voltage buffer and the current buffer.
Again using the voltage divider principal the voltage on the non-inverting input (V+) is about 2.5 volt, therefore if we start the inverting input voltage (V-) at 5 volt; the V+ is lower than the V-, this will make the comparator output will swing to the logical low (the Q8 transistor ON) and the LED will turn ON.