Veraxis
Active Member
I am new on this forum and to hobby electronics, so I apologize in advance for asking questions that probably seem exceedingly basic to the more experienced members on this site.
Firstly, I would like to ask about a part that I took out of an old phone receiver (see photo), with 4 pins and +/- markings. does anyone know what it is?
Also, this same circuit had a number of surface-mount transistors on it, but the markings seemed to be custom markings for the manufacturer (e.g. 2 or 3 digit codes like "33" or "G08"). Is there any way to test these parts or otherwise find out their specs?
Lastly, I have a number of capacitors which I have taken out of circuits for which I am unsure about the markings. (See attached photo) 1. For the three large electrolytic caps shown, is there any way to tell the capacitance and/or max voltage rating from these unconventional markings? 2. for film and tantalum capacitors is there a way to tell the maximum voltage ratings from the markings? (Or are they generally high enough that one does not need to know)? 3. for unmarked surface-mount capacitors, is there any way to figure out the maximum voltage ratings (that is, short of applying an increasing voltage until the capacitor breaks), or, again, are they generally high enough that I should not have to worry? (I tried to look at the capacitor guide on the "new to electronics FAQ", but the link was dead.)
thanks.
Firstly, I would like to ask about a part that I took out of an old phone receiver (see photo), with 4 pins and +/- markings. does anyone know what it is?
Also, this same circuit had a number of surface-mount transistors on it, but the markings seemed to be custom markings for the manufacturer (e.g. 2 or 3 digit codes like "33" or "G08"). Is there any way to test these parts or otherwise find out their specs?
Lastly, I have a number of capacitors which I have taken out of circuits for which I am unsure about the markings. (See attached photo) 1. For the three large electrolytic caps shown, is there any way to tell the capacitance and/or max voltage rating from these unconventional markings? 2. for film and tantalum capacitors is there a way to tell the maximum voltage ratings from the markings? (Or are they generally high enough that one does not need to know)? 3. for unmarked surface-mount capacitors, is there any way to figure out the maximum voltage ratings (that is, short of applying an increasing voltage until the capacitor breaks), or, again, are they generally high enough that I should not have to worry? (I tried to look at the capacitor guide on the "new to electronics FAQ", but the link was dead.)
thanks.