Question about 100uF electrolytic capacitor

[duct996]

I need a couple of 100uF electrolytic capacitor that say 50V on it for the Arduino motor shield. I have hundreds of caps at 16v and 10V and 35V and I was wondering if there was any way to put them in series or parallel to make the 100uF 50V electrolytic capacitor. Here is the link to what I am building.
**broken link removed**
Thanks for any info. I just don't want to have to order 2 things online and get charged 13.00 for shipping.

 

[dknguyen]

Putting capacitors in series will increase their working voltage while decreasing their capacitance. So four 25V 100uF caps in series will be similar to a 25uF 100V cap...similar because the parasitics will be a lot worse which isn't good for bypassing.

Putting caps in series combines capacitance while reducing lead inductance and keeping the same working voltage.

So you'd need to have a bunch of series chains in parallel with each other. Takes up a lot of room and adds a lot of lead inductance which defeats the purpose of bypassing.

 

[kchriste]

C9 will never have more than 5V on it since it decouples the Vcc line for the 74HC00 so a 10V, or more, rated part will be OK here.
C4 will have up to whatever voltage you decide to run your motor at ( 3.6V to 36V ) so a 16V rated cap would be OK if you are only feeding 12V into the V+ lead for the motor.

**broken link removed**

 

[Roff]

Putting capacitors in series will increase their working voltage while decreasing their capacitance. So four 25V 100uF caps in series will be similar to a 25uF 100V cap...similar because the parasitics will be a lot worse which isn't good for bypassing.

Putting caps in series combines capacitance while reducing lead inductance and keeping the same working voltage.

So you'd need to have a bunch of series chains in parallel with each other. Takes up a lot of room and adds a lot of lead inductance which defeats the purpose of bypassing.

Of course, you meant parallel.

 

[duct996]

THanks . I will only be running about 12 volts MAX into the motor.