5.2 KiB
CHPC: Cheap Heat Pump Controller v1.0
The CHPC a minimal cost Heat Pump (HP) controller, which can be used as provided, or can be adopted to nearly all use cases due to open source nature.
Development
State: active
Applications:
| Usage. | Brief description. | Application examples | Available protections |
|---|---|---|---|
| 1. Thermostat. | Precision thermostat. Simple and cheap. Only 1 relay and 1 temperature sensor required. |
Room heat control. Chicken coop climate control. Distillation column or Yogurt maker t. control. Else. | N/A |
| 2. Heat pump (HP) control. | Controller drives HP system components: compressor, Cold and Hot side Circulating Pumps (CP). Protects system from overload, overheat and freezing up. Drives EEV* to optimize running conditions. | DIY heat pump system. Repair module for commercial system. Water heater, house heating systems and same. | Compressor: cold start or overheat. Discharge and suction lines protection. Short-term power loss. Anti-freeze. Power overload protection. |
* under development
For more information about Heap Pumps look at Wikipedia about HP
Control interfaces:
None: Target temperature uploaded to board with firmware and cannot be changed. System used as fixed thermostat. Target temperature can be changed later with firmware re-upload.
0.96 OLED or 1602 LCD screen + buttons: Simple, local screen controlled system. Remote control is not possible.
Remote computer terminal over RS-485 line. Target temperature and running conditions under remote control. User can get stats from all T sensors. Up to 1.2 kilometer line.*
Remote automated control/stats via RS-485. Firmware was written with python scripting in mind (and real scripts at prototype 485 network).
* RS-485 specification. Hardware test succeeded on 400 meters line.
Relays:
"Thermostat":
Only 1 Relay: drives electric heater (any)
"Heat Pump". Capillary tube, TXV, EEV:
5 Relays, drives all you need:
- Compressor (can be used as external relay driver for High Power systems)
- Cold Circulating Pump (CP)
- Hot CP
- Sump Heater (optional, recommended for outdoor HP installations)
- 4-way Valve (support coming up: autumn 2019)
Temperature sensors:
- Up to 13 temperature sensors can be connected to CHPC to control all processes that you want.
- Only 1 sensor needed for "Thermostat" or "Heat Pump capillary/TXV"
- 3 sensors needed for "HP with EEV" (absolute minimum scheme)
Temperature sensors installation example (medium scheme)
Get your own CHPC:
- download PCB gerber files
- search google where to order PCB or make your own at CNC machine
- order electronic components, see BOM (Bill Of Materials) list
- solder
- install firmware
- install CHPC at your system
- enjoy
T sensors abbreviations:
This abbrevations used in interface during installation procedure
| Abbr. | Full name |
|---|---|
| Tae | after evaporator |
| Tbe | before evaporator |
| Ttarget | target |
| Tsump | sump |
| Tci | cold in |
| Tco | cold out |
| Thi | hot in |
| Tho | hot out |
| Tbc | before condenser |
| Tac | after condenser |
| Touter | outer (outdoor) |
| Ts1 | additional sensor1 |
| Ts2 | additional sensor2 |
Photos:
This is prototype 2. 1602 is the best choise.
Prototype 1.
History ) But worked well for a season.
BOM (Bill Of Materials), PCB v1.1:
| Type | Name | Quantity | Case | Comment |
|---|---|---|---|---|
| R | 10k ¼W | 2 | ||
| R | 1k ¼W | 16 | ||
| R | 100 ¼W | 1 | ||
| R | 22R ¼W | 1 | ||
| R | 10R ¼W | 1 | ||
| Cap | 0.1 uf | 4 | ||
| Cap | 22uf_16v | 4 | ||
| IC | PC817C | 2 or 4 | DIP-4 2 if you use buttons instead of inputs | |
| Conn | DIP-16 bed | 3 | DIP-16 | |
| IC | ULN2003APG | 2 | DIP-16 | |
| IC | 7805 TO-220 | 1 | TO-220 | |
| IC | 2n2222 | 1 | TO-92 | |
| - | SMIH-12VDC-SL-C | 2 | ||
| - | SRD-12VDC-SL-C | 3 | ||
| Module | TTL_485_MODULE_8PIN | 1 | ||
| Module | ARDUINO PRO MINI 328P 5V | 1 | ||
| Conn | KF128 2.54_screw_1x2 | 1 | ||
| Conn | KF128 2.54_screw_1x4 | 1 | ||
| Conn | KF128 2.54_screw_1x6 | 1 | ||
| Conn | KF128 2.54_screw_1x12 | 1 | ||
| Conn | KF128 3.81_screw_3P | 5 | ||
| Conn | KF128 5.08_screw_2P | 3 | ||
| Conn | 2.54_legs_female_x2 | 1 | like used at arduino mega | |
| Conn | 2.54_legs_female_x3 | 1 | ||
| Conn | 2.54_legs_female_x4 | 2 | ||
| Conn | 2.54_legs_female_x12 | 2 | ||
| Conn | 2.54_pins | 20 | ||
| Button | momentary switch 6x6 2 | 2 | ||
| Display | 1602 LCD with i2c interface | 1 | ||
| - | buzzer | 1 | R9.0-2P-4.0PITCH | |
| Module | LM2596S module | 0 or 1 | XX-to-12 stab | Needed only if you will use 24v as power source |
| - | power source, 12v1.25A 70x30x40 | 1 | 70x30x40 | |
| IC | ds18b20 | 6 | 1 to 13, 6 recommended as fast start | |
| Conv | usb→uart | 1 | To upload firmware | |
| - | current sensor sct-013-000 | 1 | ||
| Conv | rs485-USB | 1 | To connect CHPC < - > PC/notebook |