# PC817 Optocoupler Circuit

## Description

Three\-channel PC817 optocoupler interface converting a 24 V gate signal into isolated ESP32 measurement, local indicators, and filtered PhotoMOS event outputs\.

## Project Details

- **Owner:** speriot
- **Created:** 8/5/2026
- **Last Updated:** 10/19/2026
- **Visibility:** Public
- **Part Type:** Bipolar Transistors \- BJT
- **LCSC Part Number:** C236942
- **JLCPCB Part Class:** Extended Part
- **Package or Case Code:** TO\-92\-3\_L4\.9\-W3\.7\-P2\.54\-L
- **Functional Group:** Indicator Channel
- **Manufacturer Name:** onsemi\(安森美\)
- **Datasheet URL:** https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2410010400\_onsemi\-BC33725TA\_C236942\.pdf
- **Product Info Url:** https://lcsc\.com/product\-detail/Others\_ON\-Semicon\_BC33725TA\_ON\-Semicon\-ON\-BC33725TA\_C236942\.html
- **Manufacturer Part Number:** BC33725TA
- **Stars:** 1

## Key Components

### \* — CD14538BE

- Manufacturer Part Number: CD14538BE
- Package or Case Code: PDIP
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/user\-uploaded/c97c1c1c084ad9a36da362e0f7c05482c54d351f19262ca0973fa5b92146fc51\.pdf
- Manufacturer Name: Texas Instruments

**Pins:**
- \-TR\(1\) [pin 5]
- \-TR\(2\) [pin 11]
- \+TR\(1\) [pin 4]
- \+TR\(2\) [pin 12]
- \~\{Q2\} [pin 9]
- \~\{QI\} [pin 7]
- CX2 [pin 15]
- CXI [pin 1]
- Q2 [pin 10]
- QI [pin 6]
- RESET\(1\) [pin 3]
- RESET\(2\) [pin 13]
- RXCX\(1\) [pin 2]
- RXCX\(2\) [pin 14]
- VDD [pin 16]
- VSS [pin 8]

### BR1 — [KBP210G](https://flux.ai/adrian95/kbp210g~sjv.md)

- Manufacturer Name: Diodes Incorporated
- Datasheet URL: https://www\.diodes\.com/assets/Datasheets/ds21205\.pdf
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: KBP210G
- Part Type: Diode
- Functional Group: 24V Portal Input

**Pins:**
- \- [pin 4]
- \+ [pin 1]
- \~\_1 [pin 2]
- \~\_2 [pin 3]

### Ct1 — MKS2C041001F00JA00

- Voltage Rating: 63V
- Part Type: Capacitors
- Manufacturer Part Number: MKS2C041001F00JA00
- Tolerance: 5%
- Capacitance: 1uF

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### Ct2 — MKS2C041001F00JA00

- Voltage Rating: 63V
- Part Type: Capacitors
- Manufacturer Part Number: MKS2C041001F00JA00
- Tolerance: 5%
- Capacitance: 1uF

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### D2 — [P6KE33CA\-T](https://flux.ai/lcsc/p6ke33ca-t~825y.md)

- Manufacturer Part Number: P6KE33CA\-T
- Product Info Url: https://lcsc\.com/product\-detail/presales\_Diodes\-Incorporated\-P6KE33CA\-T\_C460611\.html
- JLCPCB Part Class: Extended Part
- Functional Group: 24V Portal Input
- Part Type: TVS
- Package or Case Code: DO\-15\_BD3\.1\-L6\.7\-P10\.70\-D0\.9\-RD
- Datasheet URL: https://www\.lcsc\.com/datasheet/lcsc\_datasheet\_2304140030\_Diodes\-Incorporated\-P6KE33CA\-T\_C460611\.pdf
- LCSC Part Number: C460611
- Manufacturer Name: DIODES\(美台\)

**Pins:**
- A [pin 2]
- C [pin 1]

### D3 — [1N4148](https://flux.ai/adrian95/1n4148~mnh.md)

- Part Type: Diode
- Datasheet URL: https://www\.onsemi\.com/pdf/datasheet/1n914\-d\.pdf
- Manufacturer Part Number: 1N4148
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Name: onsemi

**Pins:**
- anode [pin 2]
- cathode [pin 1]

### D4 — [1N4148](https://flux.ai/adrian95/1n4148~mnh.md)

- Part Type: Diode
- Datasheet URL: https://www\.onsemi\.com/pdf/datasheet/1n914\-d\.pdf
- Manufacturer Part Number: 1N4148
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Name: onsemi

**Pins:**
- anode [pin 2]
- cathode [pin 1]

### F — [Pin Header 01x01 2\.54mm Vertical \- Circular Pad](https://flux.ai/markwuflux/pin-header-01x01-2p54mm-vertical-circular-pad~vp.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Connector

**Pins:**
- P1 [pin 1]

### F1 — [MF\-R005\-AP](https://flux.ai/silicon-yard/mf-r005-ap.md)

- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/user\-uploaded/7a7dd4528c3d4bac3c3562a59e49ec6cdba122bf6397d1f9fa2963e95c50c2b6\.pdf
- Mount: Radial
- Functional Group: 24V Portal Input
- Manufacturer Part Number: MF\-R005\-AP
- Part Type: Circuit Protection Devices
- Manufacturer Name: Bourns

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### JP1 — [Jumper 2 Bridged](https://flux.ai/vasyl/jumper-2-bridged~g4.md)

- Part Type: Jumper
- Exclude from BOM: false

**Pins:**
- A [pin 1]
- B [pin 2]

### Out \+5V — [Pin Header 01x02 2\.54mm Vertical](https://flux.ai/jharwinbarrozo/generic-pin-header-01x02-2p54mm-vertical~4uy.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Connector

**Pins:**
- P1 [pin 1]
- P2 [pin 2]

### Q1 — [BC33740TA](https://flux.ai/adrian95/bc33740ta~5dt.md)

- Part Type: Transistor
- Manufacturer Name: onsemi
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: BC33740TA
- Datasheet URL: https://www\.verical\.com/datasheet/on\-semiconductor\-bjt\-\-\-general\-purpose\-BC33740TA\-4544246\.pdf

**Pins:**
- B [pin 2]
- C [pin 1]
- E [pin 3]

### Q2 — [BC33740TA](https://flux.ai/adrian95/bc33740ta~5dt.md)

- Part Type: Transistor
- Manufacturer Name: onsemi
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: BC33740TA
- Datasheet URL: https://www\.verical\.com/datasheet/on\-semiconductor\-bjt\-\-\-general\-purpose\-BC33740TA\-4544246\.pdf

**Pins:**
- B [pin 2]
- C [pin 1]
- E [pin 3]

### Q3 — [BC33740TA](https://flux.ai/adrian95/bc33740ta~5dt.md)

- Part Type: Transistor
- Manufacturer Name: onsemi
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: BC33740TA
- Datasheet URL: https://www\.verical\.com/datasheet/on\-semiconductor\-bjt\-\-\-general\-purpose\-BC33740TA\-4544246\.pdf

**Pins:**
- B [pin 2]
- C [pin 1]
- E [pin 3]

### Q4 — [BC33740TA](https://flux.ai/adrian95/bc33740ta~5dt.md)

- Part Type: Transistor
- Manufacturer Name: onsemi
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: BC33740TA
- Datasheet URL: https://www\.verical\.com/datasheet/on\-semiconductor\-bjt\-\-\-general\-purpose\-BC33740TA\-4544246\.pdf

**Pins:**
- B [pin 2]
- C [pin 1]
- E [pin 3]

### Q5 — [BC33740TA](https://flux.ai/adrian95/bc33740ta~5dt.md)

- Part Type: Transistor
- Manufacturer Name: onsemi
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: BC33740TA
- Datasheet URL: https://www\.verical\.com/datasheet/on\-semiconductor\-bjt\-\-\-general\-purpose\-BC33740TA\-4544246\.pdf

**Pins:**
- B [pin 2]
- C [pin 1]
- E [pin 3]

### Rt1 — [MRS25000C1201FCT00](https://flux.ai/lcsc/mrs25000c1201fct00~pz67.md)

- LCSC Part Number: C1366235
- Manufacturer Part Number: MF0207FRE52\-470K
- Manufacturer Name: Yageo
- Package or Case Code: RES\-TH\_BD2\.5\-L6\.5\-P10\.50\-D0\.6
- JLCPCB Part Class: Extended Part

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### Rt2 — [MRS25000C1201FCT00](https://flux.ai/lcsc/mrs25000c1201fct00~pz67.md)

- LCSC Part Number: C1366235
- Manufacturer Part Number: MF0207FRE52\-470K
- Manufacturer Name: Yageo
- Package or Case Code: RES\-TH\_BD2\.5\-L6\.5\-P10\.50\-D0\.6
- JLCPCB Part Class: Extended Part

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### S — [Pin Header 01x01 2\.54mm Vertical \- Circular Pad](https://flux.ai/markwuflux/pin-header-01x01-2p54mm-vertical-circular-pad~vp.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Connector

**Pins:**
- P1 [pin 1]

### S\_PRIME — [Pin Header 01x01 2\.54mm Vertical \- Circular Pad](https://flux.ai/markwuflux/pin-header-01x01-2p54mm-vertical-circular-pad~vp.md)

- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Connector

**Pins:**
- P1 [pin 1]

### U1\-A1 — [PC817](https://flux.ai/kicad-part-library/pc817~0c.md)

- Datasheet URL: http://www\.soselectronic\.cz/a\_info/resource/d/pc817\.pdf
- Functional Group: Isolation,ADC Channel
- Package or Case Code: DIP\-4\_W7\.62mm
- Manufacturer Part Number: PC817

**Pins:**
- \~ [pin 1]
- \~ [pin 3]
- \~ [pin 2]
- \~ [pin 4]

### U1\-B1 — [PC817](https://flux.ai/kicad-part-library/pc817~0c.md)

- Datasheet URL: http://www\.soselectronic\.cz/a\_info/resource/d/pc817\.pdf
- Functional Group: Isolation,Indicator Channel
- Package or Case Code: DIP\-4\_W7\.62mm
- Manufacturer Part Number: PC817

**Pins:**
- \~ [pin 1]
- \~ [pin 3]
- \~ [pin 2]
- \~ [pin 4]

### U1\-C1 — [PC817](https://flux.ai/kicad-part-library/pc817~0c.md)

- Datasheet URL: http://www\.soselectronic\.cz/a\_info/resource/d/pc817\.pdf
- Functional Group: Isolation,Event Channel
- Package or Case Code: DIP\-4\_W7\.62mm
- Manufacturer Part Number: PC817

**Pins:**
- \~ [pin 1]
- \~ [pin 3]
- \~ [pin 2]
- \~ [pin 4]

### U2 — [74HC14N](https://flux.ai/lcsc/74hc14n~0vtu.md)

- Datasheet URL: https://www\.htckorea\.co\.kr/Datasheet/Etc/74HC14\.pdf
- LCSC Part Number: C507186
- Part Type: Gates
- JLCPCB Part Class: Extended Part
- Manufacturer Name: HGSEMI\(华冠\)
- Manufacturer Part Number: 74HC14N
- Package or Case Code: DIP\-14\_L19\.4\-W6\.4\-P2\.54\-LS7\.6\-BL
- Functional Group: Event Channel

**Pins:**
- A1 [pin 1]
- A2 [pin 3]
- A3 [pin 5]
- A4 [pin 9]
- A5 [pin 11]
- A6 [pin 13]
- GND [pin 7]
- VCC [pin 14]
- Y1 [pin 2]
- Y2 [pin 4]
- Y3 [pin 6]
- Y4 [pin 8]
- Y5 [pin 10]
- Y6 [pin 12]

### U3 — [TLP222A](https://flux.ai/kicad-part-library/tlp222a~3x.md)

- Manufacturer Part Number: TLP222A
- Functional Group: Event Channel
- Manufacturer Name: Toshiba Corp
- Package or Case Code: DIP\-4\_W7\.62mm
- Datasheet URL: https://toshiba\.semicon\-storage\.com/info/docget\.jsp?did=17036&prodName=TLP222A

**Pins:**
- \~ [pin 1]
- \~ [pin 2]
- \~ [pin 4]
- \~ [pin 3]

### U4 — [TLP222A](https://flux.ai/kicad-part-library/tlp222a~3x.md)

- Manufacturer Part Number: TLP222A
- Functional Group: Event Channel
- Manufacturer Name: Toshiba Corp
- Package or Case Code: DIP\-4\_W7\.62mm
- Datasheet URL: https://toshiba\.semicon\-storage\.com/info/docget\.jsp?did=17036&prodName=TLP222A

**Pins:**
- \~ [pin 1]
- \~ [pin 2]
- \~ [pin 4]
- \~ [pin 3]

### U6 — L7805ABV\-DG

- Manufacturer Part Number: L7805ABV\-DG
- Datasheet URL: https://www\.st\.com/resource/en/datasheet/l78\.pdf
- Part Type: Inductors
- Manufacturer Name: STMicroelectronics

**Pins:**
- GROUND [pin 2]
- INPUT [pin 1]
- OUTPUT [pin 3]

### VOYANT\_R1 — [WP1384AD/ID](https://flux.ai/cherepanyadima/wp1384adid~2t.md)

- Part Type: LED
- Role Details: Red 24 V panel indicator with integrated current limiting; portal open
- Operating Voltage: 24V
- Datasheet URL: https://www\.kingbrightusa\.com/images/catalog/SPEC/WP934AD\-ID\.pdf
- Functional Group: Indicator Channel
- Manufacturer Part Number: WP1384AD/ID
- Manufacturer Name: Kingbright
- Role: External Indicator
- Exclude from PCB: true

**Pins:**
- 1 [pin 1]
- 2 [pin 2]

### VOYANT\_V1 — [5510607F](https://flux.ai/silicon-yard/5510607f~19.md)

- Role: External Indicator
- Exclude from PCB: true
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/user\-uploaded/ab0ded9c201fce4e6f6babd2695a84484c13cf8f4d22dd506c818a4b26f2b829\.pdf
- Functional Group: Indicator Channel
- Operating Voltage: 24V
- Role Details: Green 24 V panel indicator with integrated current limiting; portal closed
- Part Type: LED
- License: https://creativecommons\.org/licenses/by/4\.0/

**Pins:**
- A [pin 2]
- K [pin 1]

*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://flux\.ai/speriot/pc817\-optocoupler\-circuit\~ky](https://flux.ai/speriot/pc817-optocoupler-circuit~ky).*

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*Generated from [https://flux\.ai/speriot/pc817\-optocoupler\-circuit\~ky](https://flux.ai/speriot/pc817-optocoupler-circuit~ky)*