Power supplies are often limited in field environments as most of the telemetry industry uses 12 or 24 V systems, which can be a challenge when designing battery backup systems. When instrumentation and radio communication devices run on different voltage supplies, having technology that can adapt to the different voltage requirements is convenient and cost-effective. Ian Loudon, international marketing and sales manager at remote monitoring specialist, Omniflex outlines the advantages of dual-voltage power supply.
Providing both 12 and 24 V in battery standby systems can be expensive and inconvenient. Telemetry equipment is often used in the field to relay information back to control systems, but one of the big challenges is that there can often be disparity between radio and instrumentation equipment power supply voltages.
Radio equipment is often powered on a 12 V DC supply, which has the most readily available batteries. However, analytical equipment, control relays and others often require 24 V DC. Traditionally, companies would use two power supplies to address this issue. This brings about complexity, with more wiring and more maintenance time, as it can involve twice the amount of time checking on any signals and twice the cost in cabling.
Traditionally, this would require two power supply chargers and batteries for remote monitoring, therefore adding more components to the system. In addition, the draw on the 12 V DC system is different to the 24 V DC system, which drains the batteries at different rates and makes maintaining them a challenge.
Many teams would carry backup batteries with them. The most common backup battery is the sealed lead acid battery because it is relatively cheap and readily available. In high ambient temperature conditions, however, a charger will damage the batteries and shorten their lifespan, even at trickle charge. All sealed lead acid battery manufacturers specify a maximum charging current for the correct life and safe operation of sealed lead acid batteries. The PTL120C-D takes battery protection to a new level by providing a temperature sensor input where the sensor is attached to the battery. This allows the charge controller to compensate the charging rate according to the temperature of the battery, extending the battery life significantly. This maximum charging current for a battery is based on the Ampere-hour capacity of the battery.
Many conventional switch mode power supplies do not control their maximum delivered current and can cause batteries to be charged from flat with current levels that exceed the manufacturer’s recommendation. In addition, during prolonged power outages, backup batteries will eventually discharge. If the load remains connected, the batteries can enter the deep discharge phase, which can cause irreparable damage to the batteries and reduce their capacity and life expectancy.
To simplify the challenges of remote monitoring, Omniflex has developed a single product solution by developing a power supply with the PTL120C-D dual-voltage charger, with both 12 and 24 V DC output. It provides true split-rail battery charging for balanced charging to both batteries, even when 12 V loads are tapped from the battery set.
This protects the batteries from any deep discharge events as they contain mains output that is connected as an alarm to indicate loss of primary power and notify a supervisory system. The battery level is monitored through the charger and the load can be set to prevent damage, alerting a specialist to fix the problem.
With a simplified design through a compact single-unit solution, maintenance is easier and more flexible as it avoids the need for certified wiremen to change power supply through a mains-safe IEC connector.
| Tel: | +27 31 207 7466 |
| Email: | sales@omniflex.com |
| www: | www.omniflex.com |
| Articles: | More information and articles about Omniflex Remote Monitoring Specialists |
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