evol_w10lv
New Member
I'm doing a little project on MTS51 Microcomputer trainer using speaker. The task is to make schematic for my circuit and explaine values. We
are using RS232 to connect MTS51 to PC.
So here's my circuit:
I can explaine why there're diode D1, transistor T1.. but it's not clear, whats the main reason for 74LS14 there? And also, why R1 = 820 Ohms.
I don't know model of the speaker, so I don't know Ic and speakers resistance, but as I know max possible current values of D1, T1... i can
guess, that Ic is lower than 500mA. And how invertor 74LS14 effects base current?
are using RS232 to connect MTS51 to PC.
So here's my circuit:

I can explaine why there're diode D1, transistor T1.. but it's not clear, whats the main reason for 74LS14 there? And also, why R1 = 820 Ohms.
I don't know model of the speaker, so I don't know Ic and speakers resistance, but as I know max possible current values of D1, T1... i can
guess, that Ic is lower than 500mA. And how invertor 74LS14 effects base current?
Last edited: