# Prusa 24V Induction Heater Controller

## Description

A 24 V, approximately 70 W induction\-heater controller driven from the Prusa MK3S hotend heater PWM output, with ZVS power stage, fuse, surge protection, and thermal shutdown\.

## Project Details

- **Owner:** jmwilson2019
- **Created:** 9/19/2026
- **Last Updated:** 9/20/2026
- **Visibility:** Public

## Key Components

### D1 — [1N4148\-1](https://flux.ai/gaby27/1n4148-1~89.md)

- Datasheet URL: https://www\.mouser\.com/datasheet/2/308/1N914\_D\-1801484\.pdf
- Role Details: Anti\-parallel diode protects optocoupler LED against reverse voltage
- Manufacturer Name: Microchip
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Part Number: 1N4148\-1
- Part Type: Diode
- Role: Reverse Polarity Protection
- Functional Group: HEAT0 Detector and Thermal Shutdown

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

### D2 — [1\.5KE33A\-TP](https://flux.ai/lcsc/1p5ke33a-tp~vws3.md)

- Role Details: 33 V\-class unidirectional TVS after fuse; 28\.2 V stand\-off, 31\.4–34\.7 V breakdown
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc\.com/product\-detail/TVS\_MCC\-Micro\-Commercial\-Components\-MCC\-1\-5KE33A\-TP\_C712289\.html
- Manufacturer Name: MCC\(美微科\)
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2410010205\_MCC\-Micro\-Commercial\-Components\-1\-5KE33A\-TP\_C712289\.pdf
- Role: Clamping
- Package or Case Code: DO\-201\_BD5\.3\-L9\.5\-P13\.50\-D1\.4\-RD
- Functional Group: Input and Protection
- Voltage Rating: 28\.2V
- LCSC Part Number: C712289
- Part Type: TVS
- Manufacturer Part Number: 1\.5KE33A\-TP

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

### D3 — [UF4007](https://flux.ai/lcsc/uf4007~dqda.md)

- Part Type: Diodes \- Fast Recovery Rectifiers
- LCSC Part Number: C960666
- Role Details: Fast 1 A, 1000 V diode; discharges Q1 gate\-drive node from opposite drain
- Functional Group: ZVS Stage
- Package or Case Code: DO\-41\_BD2\.4\-L4\.7\-P8\.70\-D0\.9\-RD
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2407291942\_MDD\-Microdiode\-Semiconductor\-UF4007\_C960666\.pdf
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc\.com/product\-detail/Diodes\-Rectifiers\-Fast\-Recovery\_MDD\-Microdiode\-Electronics\-UF4007\_C960666\.html
- Manufacturer Name: MDD\(辰达半导体\)
- Manufacturer Part Number: UF4007
- Role: Switching

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

### D4 — [UF4007](https://flux.ai/lcsc/uf4007~dqda.md)

- Part Type: Diodes \- Fast Recovery Rectifiers
- LCSC Part Number: C960666
- Package or Case Code: DO\-41\_BD2\.4\-L4\.7\-P8\.70\-D0\.9\-RD
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2407291942\_MDD\-Microdiode\-Semiconductor\-UF4007\_C960666\.pdf
- Role Details: Fast 1 A, 1000 V diode; discharges Q2 gate\-drive node from opposite drain
- JLCPCB Part Class: Extended Part
- Product Info Url: https://lcsc\.com/product\-detail/Diodes\-Rectifiers\-Fast\-Recovery\_MDD\-Microdiode\-Electronics\-UF4007\_C960666\.html
- Manufacturer Name: MDD\(辰达半导体\)
- Role: Switching
- Manufacturer Part Number: UF4007
- Functional Group: ZVS Stage

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

### D5 — [1N4742A\-TR](https://flux.ai/jecstronic/1n4742a-tr~ua8.md)

- Part Type: Diode
- Role: Clamping
- Role Details: 12 V, 1\.3 W gate\-source zener clamp for Q1
- Manufacturer Part Number: 1N4742A\-TR
- Datasheet URL: https://www\.vishay\.com/docs/85816/1n4728a\.pdf
- Functional Group: ZVS Stage
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Name: Vishay General Semiconductor \- Diodes Division

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

### D6 — [1N4742A\-TR](https://flux.ai/jecstronic/1n4742a-tr~ua8.md)

- Part Type: Diode
- Role: Clamping
- Role Details: 12 V, 1\.3 W gate\-source zener clamp for Q2
- Manufacturer Part Number: 1N4742A\-TR
- Functional Group: ZVS Stage
- Datasheet URL: https://www\.vishay\.com/docs/85816/1n4728a\.pdf
- License: https://creativecommons\.org/licenses/by/4\.0/
- Manufacturer Name: Vishay General Semiconductor \- Diodes Division

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

### F1 — [39214000440](https://flux.ai/lcsc/39214000440~piaz.md)

- Role: Protection
- Product Info Url: https://lcsc\.com/product\-detail/Blade\-Fuses\_Littelfuse\_39214000440\_Littelfuse\-39214000440\_C178818\.html
- Package or Case Code: FUSE\-TH\_L8\.5\-W4\.0\-P5\.08\-D0\.6
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2410010331\_Littelfuse\-39214000440\_C178818\.pdf
- Manufacturer Part Number: 39214000440
- JLCPCB Part Class: Extended Part
- LCSC Part Number: C178818
- Role Details: 4 A time\-delay fuse sized for 3 A / 72 W maximum input budget
- Manufacturer Name: Littelfuse\(美国力特\)
- Part Type: Fuses with Leads \(Through Hole\)
- Current Rating: 4A
- Functional Group: Input and Protection

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

### J1 — [282837\-2](https://flux.ai/vasy_skral/282837-2~69k.md)

- Role Details: 24 V input connector; 3 A operating budget, connector rated 13\.5 A
- Datasheet URL: https://www\.te\.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=282837&DocType=Customer\+Drawing&DocLang=English
- Manufacturer Name: TE Connectivity AMP Connectors
- Manufacturer Part Number: 282837\-2
- Functional Group: Input and Protection
- Symbol Style: parametric\-v1
- Connector Type: Terminal Blocks
- Role: Power Conversion
- Part Type: Connector

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

### J2 — [282837\-2](https://flux.ai/vasy_skral/282837-2~69k.md)

- Functional Group: HEAT0 Detector and Thermal Shutdown
- Datasheet URL: https://www\.te\.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=282837&DocType=Customer\+Drawing&DocLang=English
- Connector Type: Terminal Blocks
- Manufacturer Name: TE Connectivity AMP Connectors
- Manufacturer Part Number: 282837\-2
- Symbol Style: parametric\-v1
- Part Type: Connector
- Role Details: Connect pin 1 to Einsy HEATER\+ and pin 2 to HEATER−\. The Einsy low\-side switch makes HEATER− low when commanded ON, forward\-biasing U1; a disconnected input remains OFF
- Role: Signal Mixing / Detection

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

### J3 — [282837\-2](https://flux.ai/vasy_skral/282837-2~69k.md)

- Connector Type: Terminal Blocks
- Datasheet URL: https://www\.te\.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=282837&DocType=Customer\+Drawing&DocLang=English
- Functional Group: HEAT0 Detector and Thermal Shutdown
- Manufacturer Name: TE Connectivity AMP Connectors
- Manufacturer Part Number: 282837\-2
- Symbol Style: parametric\-v1
- Role Details: External normally\-closed 90–100 °C heatsink thermal switch\. Pin 1 to THERMAL\_SW and pin 2 to THERMAL\_SW\_RETURN; an open switch or broken wire removes Q3 base drive and forces OFF
- Part Type: Connector
- Role: Protection

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

### J4 — [282837\-2](https://flux.ai/vasy_skral/282837-2~69k.md)

- Datasheet URL: https://www\.te\.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=282837&DocType=Customer\+Drawing&DocLang=English
- Manufacturer Name: TE Connectivity AMP Connectors
- Manufacturer Part Number: 282837\-2
- Symbol Style: parametric\-v1
- Functional Group: Coil and Tank
- Part Type: Connector
- Role: Prototype\-only coil connection
- Connector Type: Terminal Blocks
- Role Details: Prototype\-only terminal point; circulating\-current suitability is unconfirmed\. Use the adjacent exposed COIL\_A/COIL\_B tank\-bus pads or direct heavy\-bus/coil\-lead attachment for full\-current testing rather than relying on this terminal block\.

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

### Q1 — [IRFP4668PBFXKMA1](https://flux.ai/cherepanyadima/irfp4668pbfxkma1.md)

- Role Details: 200 V TO\-247 ZVS MOSFET; pin 1 gate, pin 2 drain/tab, pin 3 source\. Heatsink required; detuned/open\-coil drain overshoot must be verified by oscilloscope
- Part Type: Transistors
- Manufacturer Name: Infineon
- Manufacturer Part Number: IRFP4668PBFXKMA1
- Functional Group: ZVS Stage
- Role: Power Conversion
- Datasheet URL: https://www\.mouser\.ca/datasheet/2/196/Infineon\_IRFP4668\_DataSheet\_v01\_01\_EN\-3007086\.pdf
- Package or Case Code: TO

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

### Q2 — [IRFP4668PBFXKMA1](https://flux.ai/cherepanyadima/irfp4668pbfxkma1.md)

- Role: Power Conversion
- Functional Group: ZVS Stage
- Part Type: Transistors
- Manufacturer Name: Infineon
- Role Details: 200 V TO\-247 ZVS MOSFET; pin 1 gate, pin 2 drain/tab, pin 3 source\. Heatsink required; detuned/open\-coil drain overshoot must be verified by oscilloscope
- Manufacturer Part Number: IRFP4668PBFXKMA1
- Datasheet URL: https://www\.mouser\.ca/datasheet/2/196/Infineon\_IRFP4668\_DataSheet\_v01\_01\_EN\-3007086\.pdf
- Package or Case Code: TO

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

### Q3 — [MPSA92\-PBFREE](https://flux.ai/jecstronic/mpsa92-pbfree~rim.md)

- Role Details: Default\-off PNP gate\-bias supply; requires optocoupler ON and thermal switch closed
- Functional Group: Input Enable
- Datasheet URL: https://my\.centralsemi\.com/datasheets/MPSA92\-93\.PDF
- Role: Switching
- License: https://creativecommons\.org/licenses/by/4\.0/
- Part Type: Transistor
- Manufacturer Part Number: MPSA92 PBFREE
- Manufacturer Name: Central Semiconductor Corp

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

### U1 — [LTV\-817](https://flux.ai/lcsc/ltv-817~vj3o.md)

- Role Details: Optically isolated differential HEAT0 detector; LED current is about 10\.4 mA at 24 V so an ungraded LTV\-817's 50% minimum CTR can sink the approximately 5 mA enable\-path demand
- Package or Case Code: DIP\-4\_L4\.6\-W6\.5\-P2\.54\-LS7\.6\-BL
- JLCPCB Part Class: Extended Part
- Manufacturer Name: LITEON\(光宝\)
- LCSC Part Number: C125120
- Functional Group: HEAT0 Detector and Thermal Shutdown
- Datasheet URL: https://storage\.googleapis\.com/graviton\-electric\-symbols/document\_assets/lcsc/2304140030\_Lite\-On\-LTV\-817\_C125120\.pdf
- Product Info Url: https://lcsc\.com/product\-detail/SMD\-Optocouplers\_LTV\-817\_C125120\.html
- Manufacturer Part Number: LTV\-817
- Role: Isolation
- Part Type: Optocouplers \- Phototransistor Output

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

*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://flux\.ai/jmwilson2019/prusa\-24v\-induction\-heater\-controller\~0y](https://flux.ai/jmwilson2019/prusa-24v-induction-heater-controller~0y).*

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*Generated from [https://flux\.ai/jmwilson2019/prusa\-24v\-induction\-heater\-controller\~0y](https://flux.ai/jmwilson2019/prusa-24v-induction-heater-controller~0y)*