- Joined Jun 10, 2015
You can also put a resistor in series with the collector of the transistor to shift the power dissipation from your active transistor to a passive component that is less picky about operating hot. It can also provide current limiting.At such high input voltage, a series of Zener diode is not easy to get optimal.
With 90 Volt Input Voltage and A 75 Volt, 5% Zener, the 7812 could get an input voltage between 11 Volt and almost 19 Volt.
If there is to be linear regulation, I would suggest re-arranging the circuit to a series controller as the pre-regulator:
View attachment 156870
Z1 can be either a 16 or 18 volt type.
Also, take a look at @crutschow thoughts about power and voltage.
|Thread starter||Similar threads||Forum||Replies||Date|
|Q||Need help determining resistor values for a voltage divider||Homework Help||11|
|B||Need help with this circuit please tell me what resistor values for attenuator||General Electronics Chat||4|
|E||Need help finding capacitor values||General Electronics Chat||3|
|H||Need help wrinting program that uses functions to compute various math values||Homework Help||2|
|C||Need help with finding one current in circuit with a lot of elements with unknown values.||Homework Help||3|
|Need help determining resistor values for a voltage divider|
|Need help with this circuit please tell me what resistor values for attenuator|
|Need help finding capacitor values|
|Need help wrinting program that uses functions to compute various math values|
|Need help with finding one current in circuit with a lot of elements with unknown values.|