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Explore the practical uses of CFR25J 100K resistors: signal conditioning, voltage dividers, biasing, and more. South African application notes, troubleshooting, and local stock at Communica.
CFR25J 100K resistors excel in biasing, filtering, pull-up/pull-down, and voltage divider roles.
Learn resistance, tolerance, and power rating considerations for South African learners and professionals.
Access CFR25J 100K resistors from leading brands in-store or online, with rapid branch collection.
CFR25J 100K resistors are robust, general-purpose carbon film resistors, widely used in analog and digital circuits for their predictable resistance, stable power handling, and economical cost. The "CFR25J" designation indicates a Carbon Film Resistor (CFR), with a 0.25-watt (1/4W) power rating and a 5% (J) tolerance. 100K denotes 100,000 ohms resistance, a value found in signal conditioning, sensor interfacing, and control circuits across educational, hobbyist, and commercial builds in South Africa.
| Parameter | Specification | Notes |
|---|---|---|
| Resistance | 100 kOhm | 5% Tolerance (J grade) |
| Power Rating | 0.25W (250 mW) | Ambient temperature <=70 degreesC |
| Type | Axial carbon film | Through-hole mounting |
| Max Working Voltage | 250V | Common in low-power designs |
Below, see common schematic uses. Resistor values are indicative.
// Digital input pull-down example
+5V
|
[Switch]
|
(Input pin)
|
[100k ↓]
|
GND
// Voltage divider to scale 12V to 5V
Vin (12V)
|
[100kOhm]
|
[100kOhm]
|
GND
(Tap between resistors yields 6V)
For South African buyers, local availability of CFR25J 100K ensures minimal project delays and easy replacement, especially for volume builds in education and industry.
Suppose you need to halve a 10V sensor output for a 5V ADC input.
Using the voltage divider formula:
Vout = Vin x (R2 / (R1 + R2))
Vout = 10V x (100k / 200k) = 5V
This application assumes minimal ADC loading; otherwise, buffer the output with an op-amp.
For a simple RC delay:
Time constant (): = R x C = 100,000 x 0.000001 = 0.1 seconds
Verify resistor wattage in your build using:
P = V2 / R (where V is the voltage drop across the resistor)
Example: across 15V, P = (152) / 100,000 ~ 0.0023W - well below the 0.25W limit.
In South Africa, commonly stocked brands for CFR25J 100K resistors include Royal Ohm, Uniohm, and Yageo. Communica offers these and alternative values in both carbon and metal film types, with clear bin labelling and VAT invoicing for institution procurement.
Free shipping for orders over ZAR 1,000.00.
Get a full refund if you had the product for less than 7 days.
Nationwide delivery within 2 - 4 working days.
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