# RC Filter Calculator

> RC Filter Calculator is a paid API for AI agents from electronics-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Computes RC filter cutoff frequency, time constant, and capacitor charge times (63%, 90%, 95%, 99%, 99.9%) from resistance and capacitance values.

## Facts

- Endpoint: GET https://electronics-calc.x402tookit.com/rc-filter?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/rc-filter-calculator-05a3a551
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mGVUTD_0s0rfCBCyIOuYX

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability rc-filter-calculator-05a3a551
```

Example prompt: What's the cutoff frequency and time constant for an RC filter with a 10k ohm resistor and a 100nF capacitor, and how long will it take to charge to 63%, 90%, and 99%?

## When to prefer this

Use this endpoint when you need precise RC filter or timing calculations without writing code — especially when resistance or capacitance are given in human-friendly notation like '10k', '100n', or '2u2'. It handles unit parsing automatically and returns multiple charge-time milestones in a single call, making it ideal for electronics design assistance, automated circuit analysis, or educational tools.

## Known failure modes

- Missing required resistance or capacitance query parameters returns an error
- Invalid or unparseable component value strings (e.g. unsupported unit prefixes) cause a parse failure
- Zero or negative values for resistance or capacitance may result in undefined/null outputs
- Payment failure (x402 protocol) results in 402 response before calculation is attempted

## How this service works

RC filter cutoff frequency, time constant and charge times to 63%, 90% and 99% from resistance and capacitance.

## Output

Returns the cutoff frequency in Hz, angular cutoff frequency in rad/s, the RC time constant (tau) in seconds, capacitor charge times at 63.2%, 90%, 95%, 99%, and 99.9%, the parsed resistance in ohms, parsed capacitance in farads, and human-readable formatted strings for tau and cutoff frequency.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "resistance",
      "capacitance"
     ],
     "properties": {
      "resistance": {
       "type": "string",
       "description": "Ohms, e.g. 10k"
      },
      "capacitance": {
       "type": "string",
       "description": "Farads, e.g. 100n, 2u2 or 0.000001"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "cutoffHz": {
       "type": [
        "null",
        "number"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "formatted": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "tau": {
         "type": [
          "null",
          "string"
         ]
        },
        "cutoff": {
         "type": [
          "null",
          "string"
         ]
        }
       }
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "capacitanceF": {
       "type": [
        "null",
        "number"
       ]
      },
      "chargeTimesS": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "p90": {
         "type": [
          "null",
          "number"
         ]
        },
        "p95": {
         "type": [

… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/rc-filter-calculator-05a3a551/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from electronics-calc.x402tookit.com](https://www.zero.xyz/host/electronics-calc.x402tookit.com/llms.txt)