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| When consumer products like cars first needed complex controls systems like central locking and power windows, electronics were in their infancy. Electro-mechanical relays were large, hot, loud, expensive and unreliable. This was solved instead mostly by the use of "air logic." Compressed air (or sometimes vacuum) systems use miniature 3- and 4-way air valves to fulfil the needs of the logical components ''and'', or not, yes, flip-flop | When consumer products like cars first needed complex controls systems like central locking and power windows, electronics were in their infancy. Electro-mechanical relays were large, hot, loud, expensive and unreliable. This was solved instead mostly by the use of "air logic." Compressed air (or sometimes vacuum) systems use miniature 3- and 4-way air valves to fulfil the needs of the logical components ''and'', ''or'', ''not'', ''yes', and ''flip-flop'' as well as timers and delay mechanisms. Users turn dials or push buttons which feed data into the system via air instead of electricity, and the output is air or electrically-driven accessory control. Some even used these to control engine accessories, like air conditioning, fuel timing and emissions controls. |
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| While it continues to be used today, it's only for specialized industrial uses. When I encounter an air logic system, I often imagine a long-retired engineer with a shelf of industry awards and books; the father of air logic, now forgotten due to the march of technology. | While it continues to be used today, it's only for specialized industrial uses. From the 1970s onward, the now cheap and reliable integrated circuit began replacing air logic and cars were really the vanguard of the all-electronic world we live in. When I encounter an air logic system, I often imagine a long-retired engineer with a shelf of industry awards and books; the father of air logic, now forgotten due to the march of technology. |
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Electrical and electronic devices such as logic circuits, programmable controllers, and PCs normally control fluid-power and fluid-handling circuits. Such systems can also operate with “air logic,” controls that function like relays, switches, time delays, and counters. However, while the circuitry is similar, compressed air is the control medium instead of electric current. Air-logic controls are often preferred in wet or dusty environments because they pose practically no danger of explosion or electrical shock. Likewise, air controls cannot ignite explosive or flammable gases and vapors. And they’re rugged. Water can splash on the controls without affecting operations, and they tolerate dust and dirt. Air logic can also be used on machines with fluid-power components but no electrical supply. Air logic does have disadvantages. Most common is a lack of understanding among maintenance personnel on how to read schematics and troubleshoot problems. Also, air logic with long control lines responds noticeably slower than electronics. That’s because control lines longer than 10 to 15 ft fill and exhaust slowly compared to near-instantaneous electrical signals. In addition, it takes a high-quality, filtered air supply to ensure long life. Air-logic controls are basically miniature three and four-way air valves. Components include the familiar and, or, not, yes, and flip-flop elements, as well as timers and delays. Valves provide on or off functions like relays or switches, and also exhaust the spent signals. Here’s how one OEM uses air logic to its advantage. This new book is about handset-sized devices I started writing in 2013, and will not apply in some details in just a few years. In 10 years I hope the world has moved on enough that it is comically out of date. |
This book is about handset-sized mobile phones and similar devices. I started writing in 2013, and expect it will not apply in some details in just a few years. In 10 years I hope the world has moved on enough that it is comically out of date. |
When consumer products like cars first needed complex controls systems like central locking and power windows, electronics were in their infancy. Electro-mechanical relays were large, hot, loud, expensive and unreliable. This was solved instead mostly by the use of "air logic." Compressed air (or sometimes vacuum) systems use miniature 3- and 4-way air valves to fulfil the needs of the logical components and, or, not, yes', and flip-flop as well as timers and delay mechanisms. Users turn dials or push buttons which feed data into the system via air instead of electricity, and the output is air or electrically-driven accessory control. Some even used these to control engine accessories, like air conditioning, fuel timing and emissions controls. While it continues to be used today, it's only for specialized industrial uses. From the 1970s onward, the now cheap and reliable integrated circuit began replacing air logic and cars were really the vanguard of the all-electronic world we live in. When I encounter an air logic system, I often imagine a long-retired engineer with a shelf of industry awards and books; the father of air logic, now forgotten due to the march of technology. This book is about handset-sized mobile phones and similar devices. I started writing in 2013, and expect it will not apply in some details in just a few years. In 10 years I hope the world has moved on enough that it is comically out of date. Keep yourself educated, keep up to date with trends and technology, and never be so in love with a particular solution, or way of working that you lose sight of the changing world.