From ed6cee1a9734591dfa54ce6928f8818342317abd Mon Sep 17 00:00:00 2001 From: 0xPIT Date: Fri, 13 Jun 2014 14:28:32 +0200 Subject: [PATCH] update readme --- README.md | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/README.md b/README.md index 7afd772..a751292 100644 --- a/README.md +++ b/README.md @@ -15,27 +15,27 @@ Arduino-based reflow oven controller with: * drive two AC loads, such as heater and fan (c) 2014 Karl Pitrich -based on a project (c) 2013 Ed Simmons +in part based on a project (c) 2013 Ed Simmons Introduction ==================== -As I believe it is not wise to have a mess of wiring and tiny breakout-boards for operating mains powered equipment, I've decided to design custom board with easily obtainable components. - This Reflow Oven Controller relies on an [Arduino Pro Micro], which is similar to the Leonardo and easily obtainable on eb*y for less than $10, plus my custom shield, which is actually more like a motherboard. +As I believe it is not wise to have a mess of wiring and tiny breakout-boards for operating mains powered equipment, I've decided to design custom board with easily obtainable components. + The hardware can be found in the [folder hardware], including the Eagle schematics and PCB layout files. It should fit the freemium version of Eagle. Here are preview images: ![PCB][ImgPCB] ![Schematic][ImgSCH] -The board contains the Arduino Pro Micro, very simple [Zero crossing] detection circuit, used to align control logic to mains frequency, two [MAX31855] thermocouple-to-digital converters and two [Sharp S202S01] PCB-mount solid state relays, mounted on cheap [Fischer SK409 50,8] heat sinks. The current software uses only one of the thermocouples, so you need to populate one IC only. +The board contains the [Arduino Pro Micro], very simple [Zero crossing] detection circuit, used to align control logic to mains frequency, two [MAX31855] thermocouple-to-digital converters and two [Sharp S202S01] PCB-mount solid state relays, mounted on cheap [Fischer SK409 50,8] heat sinks. The current software uses only one of the thermocouples, so you need to populate one IC only. The software uses [PID] control of the heater and fan output for improved temperature stability. The heater AC load is controlled using [Wave Packet] control, in order to minimize RF interference and load on the relay. Please note that all important timings are *based on the mains frequency*, so the circuit will **not work** properly without mains connection. -For testing, I've added an additional timer to simulate the zero-crossings, in order to run the software without being connected to mains. Please note that everything is tuned to 50Hz mains, if you live in a retro-country 60Hz mains and probably even imperial units, you need to adjust the source to fit. +For testing, I've added an additional timer to simulate the zero-crossings, in order to run the software without being connected to mains. Please note that everything is tuned to 50Hz mains, if you live in a retro-country 60Hz mains (and probably even imperial units), you need to adjust the source so that the timings fit. Screenshots and usage information ========