Replacing 1/2w carbon resistor with 1/4w
- DjPsychic
- Breadboard Brother
Hello,
I'm in the process of modding a vintage Thomas Organ Crybaby. I was going to use some 1/4W carbon comp resistors that I already have to replace some of the stock 1/2W for mods.
Is this ok or should I be using matching 1/2W?
Thank you
I'm in the process of modding a vintage Thomas Organ Crybaby. I was going to use some 1/4W carbon comp resistors that I already have to replace some of the stock 1/2W for mods.
Is this ok or should I be using matching 1/2W?
Thank you
- The G
- Grease Monkey
I just took a second look at the Ohm's Law and... I don't get it ¯\_(ツ)_/¯. As I see it, resistor parameters that are usually relevant are its electrical resistance, maximum power dissipation and noise. I presume the OP will replace with resistors of the same electrical resistance, but half the maximum power dissipation. What am I missing?
To the OP: if you're modding the pedal and not aiming for the vintage correctness, why wouldn't you use metal film resistors (lower noise)?
- plush
- Cap Cooler
You choose your resistor power rating based on it's maximum power dissipation in its current application, which can be calculated using ohm's law.The G wrote: ↑25 Oct 2020, 12:28 I just took a second look at the Ohm's Law and... I don't get it ¯\_(ツ)_/¯
- The G
- Grease Monkey
Thank you. So, the full process would've been
- OP provides the schematic.
- Having resistor values and supply voltages, one could calculate the dissipated power for each resistor using the power formula P = I × V = R × I2 = V2 ⁄ R.
Or we could calculate that a resistor needs to have a resistance less than 324Ω to dissipate more than 250mW (1/4W). Thus, assuming that all Thomas Organ Cry Baby resistors have higher resistance than that, one can replace all resistors with their 1/4W variants, without calculating the voltage across each resistor.
- andy-h-h
- Breadboard Brother
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