Watt per volt to Franklin second
W/V
Fr.s
Conversion History
| Conversion | Reuse | Delete |
|---|---|---|
1 W/V (Watt per volt) → 2997924536.84314349176065409917 Fr.s (Franklin second) Just now |
Quick Reference Table (Watt per volt to Franklin second)
| Watt per volt (W/V) | Franklin second (Fr.s) |
|---|---|
| 0.1 | 299,792,453.68431434917606540992 |
| 1 | 2,997,924,536.84314349176065409917 |
| 5 | 14,989,622,684.21571745880327049584 |
| 10 | 29,979,245,368.43143491760654099167 |
| 20 | 59,958,490,736.86286983521308198334 |
| 100 | 299,792,453,684.31434917606540991671 |
About Watt per volt (W/V)
The watt per volt (W/V) equals one ampere, derived from the power relationship P = IV rearranged as I = P/V. A device consuming 60 W at 120 V draws 0.5 W/V = 0.5 A. The W/V form is most useful when calculating branch currents from known power ratings and supply voltages — for appliance load calculations, transformer secondary currents, or power budget analysis on a circuit board. Numerically identical to the ampere, it provides an alternative view emphasising the power-per-volt character of current and is common in power electronics and electrical installation design.
A 100 W light bulb on a 230 V supply draws approximately 0.43 W/V. A 60 W laptop adapter at 20 V delivers 3 W/V to the device.
About Franklin second (Fr.s)
The franklin per second (Fr/s) equals approximately 3.335641×10⁻¹⁰ amperes. The franklin (Fr), also called the statcoulomb, is the CGS-ESU unit of electric charge; one franklin per second of charge flow constitutes one statampere of current. The conversion factor arises from c/10 in CGS (where c ≈ 3×10¹⁰ cm/s), linking the ESU and SI charge systems. The franklin itself honors Benjamin Franklin, whose experiments established the convention of positive and negative electric charge. The unit appears in older electrostatics and radiation dosimetry literature and is otherwise of historical interest only.
1 Fr/s ≈ 3.336×10⁻¹⁰ A. One ampere of current corresponds to approximately 3×10⁹ franklin per second.
Watt per volt – Frequently Asked Questions
Why would an electrician think in watts per volt?
When sizing circuits, electricians know the appliance power (watts from the nameplate) and the supply voltage (120 V or 230 V). Dividing watts by volts gives the current in amps — which is what determines wire gauge and breaker size. "1,800 W ÷ 120 V = 15 A, so I need a 20 A circuit" is daily electrician math.
Is watts per volt ever written on any product label?
No — product labels list watts, volts, and amps separately. The W/V expression lives in textbooks and engineering calculations. But every time you read "1,500 W, 120 V" on a space heater and mentally divide to get 12.5 A, you are computing watts per volt without calling it that.
Does the watts-per-volt calculation work for AC power?
Only approximately. For AC, real power (watts) = V × I × power factor. So I = W / (V × PF). A motor rated at 1,000 W with a power factor of 0.85 on 230 V actually draws 1,000 / (230 × 0.85) = 5.1 A, not the 4.35 A that simple W/V would suggest. Always account for power factor in AC circuits.
How does watts per volt help with USB power delivery calculations?
USB PD negotiates voltage levels (5 V, 9 V, 15 V, 20 V) and maximum power (up to 240 W). Dividing the negotiated power by voltage gives the cable current: 100 W at 20 V = 5 A, requiring a 5 A rated cable. At 5 V the same 100 W would need 20 A — which is why PD uses higher voltages.
What is the relationship between watts per volt and Ohm's law?
From P = IV and V = IR, you get I = P/V = V/R = P^(1/2)/R^(1/2). The W/V form is just one of many equivalent expressions for current. Which one you use depends on what you know: power and voltage gives W/V, voltage and resistance gives V/R (Ohm's law directly).
Franklin second – Frequently Asked Questions
Who was Benjamin Franklin and why is a charge unit named after him?
Franklin (1706–1790) was the American polymath who proved lightning is electrical with his famous kite experiment in 1752. He introduced the convention of "positive" and "negative" charge that we still use today. He arbitrarily assigned positive to the charge on glass rubbed with silk — which turned out to be a deficit of electrons, giving us the unfortunate convention that current flows opposite to electron motion.
Why is the franklin still referenced in the definition of the roentgen radiation unit?
The roentgen (R) was defined in 1928 as the radiation exposure producing 1 ESU of charge (1 franklin ≈ 3.336 × 10⁻¹⁰ C) per cm³ of dry air at STP. This CGS-era definition stuck because radiation safety regulations were already built around it. Even though the SI gray replaced the roentgen for dosimetry, the roentgen — and its franklin-based definition — persists in US regulatory and medical imaging contexts.
Why does the franklin appear in radiation dosimetry?
The legacy unit of radiation exposure, the roentgen (R), is defined as the amount of X-ray or gamma radiation that produces 1 esu of charge (1 franklin) per cubic centimeter of dry air at STP. This definition dates from the 1920s when CGS-ESU was standard. Modern dosimetry uses grays and sieverts, but the roentgen and its franklin-based definition persist in some medical and regulatory contexts.
How does franklin per second compare to everyday currents?
One Fr/s is about 0.33 nanoamperes — less current than a sleeping microcontroller draws. To equal the 1 A flowing through a phone charger cable, you would need about 3 billion franklins per second. The unit is spectacularly impractical for anything beyond electrostatics calculations.
Did Benjamin Franklin actually get the sign of electric charge wrong?
Sort of. He labelled the charge on glass rubbed with silk as "positive," not knowing it was caused by removing electrons. When Thomson discovered the electron in 1897, it turned out electrons carry what Franklin called negative charge. So conventional current flows from + to −, opposite to actual electron flow. Engineers and physicists have lived with this "mistake" for over 250 years.