Led Resistor

{
  "asOf": "2026-10-11T08:33:11.465Z",
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "e12": {
    "above": 150,
    "below": 150,
    "closest": 150
  },
  "e24": {
    "above": 150,
    "below": 150,
    "closest": 150
  },
  "exactPowerMw": 60,
  "ledsInSeries": 1,
  "notChecked": [
    "the LED's absolute maximum current and the supply's tolerance",
    "forward voltage varies by part and temperature (read the datasheet)",
    "…2 more"
  ],
  "reasons": [
    "Round UP to the next standard value so the current stays at or below the target.",
    "Use a resistor rated at least 2x its dissipation (a 1/4 W part is plenty for 60 mW)."
  ],
  "recommended": {
    "actualCurrentMa": 20,
    "ohms": 150,
    "resistorPowerMw": 60,
    "series": "E24 next value up"
  },
  "resistanceOhm": 150,
  "source": "computed locally",
  "summary": "R = 150 ohm for 20 mA (3 V across the resistor); use 150 ohm (next standard E24 value up) for 20 mA, dissipating 60 mW.",
  "verdict": "COMPUTED",
  "voltageAcrossResistorV": 3
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://electronics-calc.x402tookit.com/led-resistor?currentMa=20&forwardV=2&supplyV=5'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://electronics-calc.x402tookit.com/led-resistor?currentMa=20&forwardV=2&supplyV=5' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Felectronics-calc.x402tookit.com%2Fled-resistor
const res = await pay("https://electronics-calc.x402tookit.com/led-resistor?currentMa=20&forwardV=2&supplyV=5");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://electronics-calc.x402tookit.com/led-resistor?currentMa=20&forwardV=2&supplyV=5")
    print(res.status_code, res.text)